System and method for responding to driver behavior

ABSTRACT

Methods of assessing driver behavior include monitoring vehicle systems and driver monitoring systems to accommodate for a driver&#39;s slow reaction time, attention lapse and/or alertness. When it is determined that a driver is drowsy, for example, the response system may modify the operation of one or more vehicle systems. The systems that may be modified include: visual devices, audio devices, tactile devices, antilock brake systems, automatic brake prefill systems, brake assist systems, auto cruise control systems, electronic stability control systems, collision warning systems, lane keep assist systems, blind spot indicator systems, electronic pretensioning systems and climate control systems.

This application is a continuation of U.S. application Ser. No.14/977,787 filed Dec. 22, 2015, published as US 2016/0152233, and nowissued as U.S. Pat. No. 9,855,945, which is a continuation of U.S.application Ser. No. 13/843,249 filed on Mar. 15, 2013, published as US2013/0245886, and now issued as U.S. Pat. No. 9,296,382, which is acontinuation of U.S. application Ser. No. 13/030,637 filed on Feb. 18,2011, now issued as U.S. Pat. No. 8,698,639, all of which are expresslyincorporated herein by reference.

BACKGROUND

The current embodiment relates to motor vehicles and in particular to asystem and method for responding to driver behavior.

Motor vehicles are operated by drivers in various conditions. Lack ofsleep, monotonous road conditions, use of items, or health-relatedconditions can increase the likelihood that a driver may become drowsyor inattentive while driving. When drowsy or inattentive, drivers mayhave delayed reaction times. A drowsy driver also has an increasedlikelihood of falling asleep at the wheel, which can cause potentialharm to the driver, other vehicle occupants and occupants in nearbyvehicles or pedestrians.

SUMMARY

In one aspect, a method of controlling one or more vehicle systems in amotor vehicle includes receiving monitoring information, determining ifa driver is drowsy and modifying the control of one or more vehiclesystems when the driver is drowsy.

In another aspect, a method of controlling a vehicle system in a motorvehicle includes receiving monitoring information, determining a levelof drowsiness and modifying the control of the vehicle system when thedriver is drowsy according to the level of drowsiness.

In another aspect, a method of controlling a vehicle system in a motorvehicle includes receiving information from a sensor, where the sensoris capable of detecting information about the autonomic nervous systemof a driver. The method also includes determining if the driver isdrowsy and modifying the control of the vehicle system when the driveris drowsy.

In another aspect, a method of controlling a vehicle system in a motorvehicle includes receiving monitoring information and determining a bodystate index for a driver, where the body state index characterizesdrowsiness. The method also includes determining a control parameterusing the body state index and operating a vehicle system using thecontrol parameter.

Other systems, methods, features and advantages will be, or will become,apparent to one of ordinary skill in the art upon examination of thefollowing figures and detailed description. It is intended that all suchadditional systems, methods, features and advantages be included withinthis description and this summary, be within the scope of theembodiments, and be protected by the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments can be better understood with reference to the followingdrawings and detailed description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the embodiments. Moreover, in the figures, likereference numerals designate corresponding parts throughout thedifferent views.

FIG. 1 is a schematic view of an embodiment of various components andsystems for a motor vehicle;

FIG. 2 is a schematic view of an embodiment of various different vehiclesystems;

FIG. 3 is a schematic view of an embodiment of various differentautonomic monitoring systems;

FIG. 4 is an embodiment of a process of controlling vehicle systemsaccording to driver behavior;

FIG. 5 is a table showing the impact of a response system on variousvehicle systems;

FIG. 6 is an embodiment of a process of determining a level ofdrowsiness and operating one or more vehicle systems;

FIG. 7 is an embodiment of a process for operating a vehicle systemusing a control parameter;

FIG. 8 is an embodiment of a relationship between body state index and acontrol coefficient;

FIG. 9 is an embodiment of a calculation unit for determining a controlparameter;

FIG. 10 is an embodiment of a relationship between body state index anda vehicle system status;

FIG. 11 is a schematic view of an embodiment of a method of monitoringthe eye movement of a driver to help determine if a driver is drowsy;

FIG. 12 is an embodiment of a process of monitoring eye movement of adriver to determine if the driver is drowsy;

FIG. 13 is a schematic view of an embodiment of a method of monitoringthe head movement of a driver to determine if the driver is drowsy;

FIG. 14 is an embodiment of a process of monitoring the head movement ofa driver to determine if the driver is drowsy;

FIG. 15 is a schematic view of an embodiment of a method of monitoringthe distance between the driver's head and a headrest to determine ifthe driver is drowsy;

FIG. 16 is an embodiment of a process of monitoring the distance betweenthe driver's head and a headrest to determine if the driver is drowsy;

FIG. 17 is a schematic view of an embodiment of a method of monitoringsteering information to determine if a driver is drowsy;

FIG. 18 is an embodiment of a process of monitoring steering informationto determine if a driver is drowsy;

FIG. 19 is a schematic view of an embodiment of a method of monitoringlane departure information to determine if a driver is drowsy;

FIG. 20 is an embodiment of a process of monitoring lane departureinformation to determine if a driver is drowsy;

FIG. 21 is a schematic view of an embodiment of a method of monitoringautonomic nervous system information to determine if a driver is drowsy;

FIG. 22 is an embodiment of a process of monitoring autonomic nervoussystem information to determine if a driver is drowsy;

FIG. 23 is a schematic view of an embodiment of a method of modifyingthe operation of a power steering system when a driver is drowsy;

FIG. 24 is a schematic view of an embodiment of a method of modifyingthe operation of a power steering system when a driver is drowsy;

FIG. 25 is an embodiment of a process of controlling a power steeringsystem when a driver is drowsy;

FIG. 26 is an embodiment of a detailed process for controlling powersteering assistance in response to driver behavior;

FIG. 27 is a schematic view of an embodiment of a method of modifyingthe operation of a climate control system when a driver is drowsy;

FIG. 28 is a schematic view of an embodiment of a method of modifyingthe operation of a climate control system when a driver is drowsy;

FIG. 29 is an embodiment of a process of controlling a climate controlsystem when a driver is drowsy;

FIG. 30 is a schematic view of an embodiment of various provisions thatcan be used to wake a drowsy driver;

FIG. 31 is a schematic view of an embodiment of a method of waking up adrowsy driver using tactile devices, visual devices and audio devices;

FIG. 32 is an embodiment of a process for waking up a drowsy driverusing tactile devices, visual devices and audio devices;

FIG. 33 is a schematic view of an electronic pretensioning system for amotor vehicle;

FIG. 34 is a schematic view of a method of waking up a driver using theelectronic pretensioning system of FIG. 33;

FIG. 35 is an embodiment of a process of controlling an electronicpretensioning system according to driver behavior;

FIG. 36 is a schematic view of an embodiment of a method of operating anantilock braking system when a driver is fully awake;

FIG. 37 is a schematic view of an embodiment of a method of modifyingthe operation of the antilock braking system of FIG. 36 when the driveris drowsy;

FIG. 38 is an embodiment of a process of modifying the operation of anantilock braking system according to driver behavior;

FIG. 39 is an embodiment of a process of modifying the operation of abrake system according to driver behavior;

FIG. 40 is an embodiment of a process of modifying the operation of abrake assist system according to driver behavior;

FIG. 41 is an embodiment of a process for controlling brake assistaccording to driver behavior;

FIG. 42 is an embodiment of a process for determining an activationcoefficient for brake assist;

FIG. 43 is a schematic view of an embodiment of a motor vehicleoperating with an electronic stability control system;

FIG. 44 is a schematic view of an embodiment of a method of modifyingthe operation of the electronic control assist system of FIG. 43 whenthe driver is drowsy;

FIG. 45 is an embodiment of a process of modifying the operation of anelectronic stability control system according to driver behavior;

FIG. 46 is an embodiment of a process for controlling an electronicstability control system in response to driver behavior;

FIG. 47 is an embodiment of a process for setting an activationthreshold for an electronic stability control system;

FIG. 48 is a schematic view of an embodiment of a motor vehicle equippedwith a collision warning system;

FIG. 49 is an embodiment of a process of modifying the control of acollision warning system according to driver behavior;

FIG. 50 is an embodiment of a detailed process of modifying the controlof a collision warning system according to driver behavior;

FIG. 51 is a schematic view of an embodiment of a motor vehicleoperating with an auto cruise control system;

FIG. 52 is a schematic view of an embodiment of a method of modifyingthe control of the auto cruise control system of FIG. 51 according todriver behavior;

FIG. 53 is an embodiment of a process of modifying the control of anauto cruise control system according to driver behavior;

FIG. 54 is an embodiment of a process of modifying operation of anautomatic cruise control system in response to driver behavior;

FIG. 55 is an embodiment of a process of modifying a cruising speed of avehicle according to driver behavior;

FIG. 56 is an embodiment of a process for controlling a low speed followfunction associated with cruise control;

FIG. 57 is a schematic view of an embodiment of a motor vehicleoperating with a lane departure warning system;

FIG. 58 is a schematic view of an embodiment of a method of modifyingthe control of the lane departure warning system of FIG. 57 when thedriver is drowsy;

FIG. 59 is an embodiment of a process of modifying the control of a lanedeparture warning system according to driver behavior;

FIG. 60 is an embodiment of a process of modifying the operation of alane departure warning system in response to driver behavior;

FIG. 61 is an embodiment of a process for setting a road crossingthreshold;

FIG. 62 is an embodiment of a process of modifying operation of a lanekeep assist system in response to driver behavior;

FIG. 63 is a schematic view of an embodiment in which a blind spotindicator system is active;

FIG. 64 is a schematic view of an embodiment in which a blind spotindicator system is active and a blind spot monitoring zone is increasedin response to driver behavior;

FIG. 65 is an embodiment of a process of modifying the control of ablind spot indicator system;

FIG. 66 is an embodiment of a process for controlling a blind spotindicator system is response to driver behavior;

FIG. 67 is an embodiment of a process for determining a zone thresholdfor a blind spot indicator system;

FIG. 68 is an embodiment of a chart for selecting warning type accordingto body state index;

FIG. 69 is a schematic view of an embodiment of a collision mitigationbraking system in which no warning is provided when the driver is alert;

FIG. 70 is a schematic view of an embodiment of a collision mitigationbraking system in which a warning is provided when the driver is drowsy;

FIG. 71 is a schematic view of an embodiment of a collision mitigationbraking system in which no automatic seatbelt pretensioning is providedwhen the driver is alert;

FIG. 72 is a schematic view of an embodiment of a collision mitigationbraking system in which automatic seatbelt pretensioning is providedwhen the driver is drowsy;

FIG. 73 is an embodiment of a process for controlling a collisionmitigation braking system in response to driver behavior;

FIG. 74 is an embodiment of a process for setting time to collisionthresholds;

FIG. 75 is an embodiment of a process for operating a collisionmitigation braking system during a first warning stage;

FIG. 76 is an embodiment of a process for operating a collisionmitigation braking system during a second warning stage; and

FIG. 77 is an embodiment of a process for operating a navigation systemaccording to driver monitoring.

DETAILED DESCRIPTION

FIG. 1 is a schematic view of an embodiment of various components for amotor vehicle 100. The term “motor vehicle” as used throughout thisdetailed description and in the claims refers to any moving vehicle thatis capable of carrying one or more human occupants and is powered by anyform of energy. The term “motor vehicle” includes, but is not limitedto: cars, trucks, vans, minivans, SUVs, motorcycles, scooters, boats,personal watercraft, and aircraft.

In some cases, a motor vehicle includes one or more engines. The term“engine” as used throughout the specification and claims refers to anydevice or machine that is capable of converting energy. In some cases,potential energy is converted to kinetic energy. For example, energyconversion can include a situation where the chemical potential energyof a fuel or fuel cell is converted into rotational kinetic energy orwhere electrical potential energy is converted into rotational kineticenergy. Engines can also include provisions for converting kineticenergy into potential energy. For example, some engines includeregenerative braking systems where kinetic energy from a drive train isconverted into potential energy. Engines can also include devices thatconvert solar or nuclear energy into another form of energy. Someexamples of engines include, but are not limited to: internal combustionengines, electric motors, solar energy converters, turbines, nuclearpower plants, and hybrid systems that combine two or more differenttypes of energy conversion processes.

For purposes of clarity, only some components of motor vehicle 100 areshown in the current embodiment. Furthermore, it will be understood thatin other embodiments some of the components may be optional.Additionally, it will be understood that in other embodiments, any otherarrangements of the components illustrated here can be used for poweringmotor vehicle 100.

Generally, motor vehicle 100 may be propelled by any power source. Insome embodiments, motor vehicle 100 may be configured as a hybridvehicle that uses two or more power sources. In other embodiments, motorvehicle 100 may use a single power source, such as an engine.

In one embodiment, motor vehicle 100 can include engine 102. Generally,the number of cylinders in engine 102 could vary. In some cases, engine102 could include six cylinders. In some cases, engine 102 could be athree cylinder, four cylinder or eight cylinder engine. In still othercases, engine 102 could have any other number of cylinders.

In some embodiments, motor vehicle 100 may include provisions forcommunicating, and in some cases controlling, the various componentsassociated with engine 102 and/or other systems of motor vehicle 100. Insome embodiments, motor vehicle 100 may include a computer or similardevice. In the current embodiment, motor vehicle 100 may includeelectronic control unit 150, hereby referred to as ECU 150. In oneembodiment, ECU 150 may be configured to communicate with, and/orcontrol, various components of motor vehicle 100.

ECU 150 may include a microprocessor, RAM, ROM, and software all servingto monitor and supervise various parameters of the engine, as well asother components or systems of motor vehicle 100. For example, ECU 150is capable of receiving signals from numerous sensors, devices, andsystems located in the engine. The output of various devices is sent toECU 150 where the device signals may be stored in an electronic storage,such as RAM. Both current and electronically stored signals may beprocessed by a central processing unit (CPU) in accordance with softwarestored in an electronic memory, such as ROM.

ECU 150 may include a number of ports that facilitate the input andoutput of information and power. The term “port” as used throughout thisdetailed description and in the claims refers to any interface or sharedboundary between two conductors. In some cases, ports can facilitate theinsertion and removal of conductors. Examples of these types of portsinclude mechanical connectors. In other cases, ports are interfaces thatgenerally do not provide easy insertion or removal. Examples of thesetypes of ports include soldering or electric traces on circuit boards.

All of the following ports and provisions associated with ECU 150 areoptional. Some embodiments may include a given port or provision, whileothers may exclude it. The following description discloses many of thepossible ports and provisions that can be used, however, it should bekept in mind that not every port or provision must be used or includedin a given embodiment.

In some embodiments, ECU 150 can include provisions for communicatingand/or controlling various systems associated with engine 102. In oneembodiment, ECU 150 can include port 151 for receiving various kinds ofsteering information. In some cases, ECU 150 may communicate withelectronic power steering system 160, also referred to as EPS 160,through port 151. EPS 160 may comprise various components and devicesutilized for providing steering assistance. In some cases, for example,EPS 160 may include an assist motor as well as other provisions forproviding steering assistance to a driver. In addition, EPS 160 could beassociated with various sensors including torque sensors, steering anglesensors as well as other kinds of sensors. Examples of electronic powersteering systems are disclosed in Kobayashi, U.S. Pat. No. 7,497,471,filed Feb. 27, 2006 as well as Kobayashi, U.S. Pat. No. 7,497,299, filedFeb. 27, 2006, the entirety of both being hereby incorporated byreference.

In some embodiments, ECU 150 can include provisions for receivingvarious kinds of optical information. In one embodiment, ECU 150 caninclude port 152 for receiving information from one or more opticalsensing devices, such as optical sensing device 162. Optical sensingdevice 162 could be any kind of optical device including a digitalcamera, video camera, infrared sensor, laser sensor, as well as anyother device capable of detecting optical information. In oneembodiment, optical sensing device 162 could be a video camera. Inaddition, in some cases, ECU 150 could include port 159 forcommunicating with thermal sensing device 163. Thermal sensing device163 may be configured to detect thermal information. In some cases,thermal sensing device 163 and optical sensing device 162 could becombined into a single sensor.

Generally, one or more optical sensing devices and/or thermal sensingdevices could be associated with any portion of a motor vehicle. In somecases, an optical sensing device could be mounted to the roof of avehicle cabin. In other cases, an optical sensing device could bemounted in a vehicle dashboard. Moreover, in some cases, multipleoptical sensing devices could be installed inside a motor vehicle toprovide viewpoints of a driver or occupant from multiple differentangles. In one embodiment, optical sensing device 162 may be installedin a portion of motor vehicle 100 so that optical sensing device 162 cancapture images of the face and/or head of a driver or occupant.Similarly, thermal sensing device 163 could be located in any portion ofmotor vehicle 100 including a dashboard, roof or in any other portion.Thermal sensing device 163 may also be located so as to provide a viewof the face and/or head of a driver.

In some embodiments, ECU 150 can include provisions for receivinginformation about the location of a driver's head. In one embodiment,ECU 150 can include port 135 for receiving information related to thedistance between a driver's head and headrest 137. In some cases, thisinformation can be received from proximity sensor 134. Proximity sensor134 could be any type of sensor configured to detect the distancebetween the driver's head and headrest 137. In some cases, proximitysensor 134 could be a capacitor. In other cases, proximity sensor 134could be a laser sensing device. In still other cases, any other typesof proximity sensors known in the art could be used for proximity sensor134. Moreover, in other embodiments, proximity sensor 134 could be usedto detect the distance between any part of the driver and any portion ofmotor vehicle 100 including, but not limited to: a headrest, a seat, asteering wheel, a roof or ceiling, a driver side door, a dashboard, acentral console as well as any other portion of motor vehicle 100.

In some embodiments, ECU 150 can include provisions for receivinginformation about the biological state of a driver. For example, ECU 150could receive information related to the autonomic nervous system (orvisceral nervous system) of a driver. In one embodiment, ECU 150 mayinclude port 153 for receiving information about the state of a driverfrom bio-monitoring sensor 164. Examples of different information abouta driver that could be received from bio-monitoring sensor 164 include,but are not limited to: heart information, such as, heart rate, bloodpressure, oxygen content, etc., brain information, such as,electroencephalogram (EEG) measurements, functional near infraredspectroscopy (fNIRS), functional magnetic resonance imaging (fMRI), etc,digestion information, respiration rate information, salivationinformation, perspiration information, pupil dilation information, aswell as other kinds of information related to the autonomic nervoussystem or other biological systems of the driver.

Generally, a bio-monitoring sensor could be disposed in any portion of amotor vehicle. In some cases, a bio-monitoring sensor could be disposedin a location proximate to a driver. For example, in one embodiment,bio-monitoring sensor 164 could be located within or on the surface ofdriver seat 190. In other embodiments, however, bio-monitoring sensor164 could be located in any other portion of motor vehicle 100,including, but not limited to: a steering wheel, a headrest, an armrest,dashboard, rear-view mirror as well as any other location. Moreover, insome cases, bio-monitoring sensor 164 may be a portable sensor that isworn by a driver, associated with a portable device located in proximityto the driver, such as a smart phone or similar device or associatedwith an article of clothing worn by the driver.

In some embodiments, ECU 150 can include provisions for communicatingwith and/or controlling various visual devices. Visual devices includeany devices that are capable of displaying information in a visualmanner. These devices can include lights (such as dashboard lights,cabin lights, etc.), visual indicators, video screens (such as anavigation screen or touch screen), as well as any other visual devices.In one embodiment, ECU 150 includes port 154 for communicating withvisual devices 166.

In some embodiments, ECU 150 may include provisions for receiving inputfrom a user. For example, in some embodiments, ECU 150 can include port158 for receiving information from user input device 111. In some cases,user input device 111 could comprise one or more buttons, switches, atouch screen, touch pad, dial, pointer or any other type of inputdevice. For example, in one embodiment, input device 111 could be akeyboard or keypad. In another embodiment, input device 111 could be atouch screen. In one embodiment, input device 111 could be an ON/OFFswitch. In some cases, input device 111 could be used to turn on or offany body state monitoring devices associated with the vehicle or driver.For example, in an embodiment where an optical sensor is used to detectbody state information, input device 111 could be used to switch thistype of monitoring on or off. In embodiments using multiple monitoringdevices, input device 111 could be used to simultaneously turn on or offall the different types of monitoring associated with these monitoringdevices. In other embodiments, input device 111 could be used toselectively turn on or off some monitoring devices but not others.

In some embodiments, ECU 150 may include ports for communicating withand/or controlling various different engine components or systems.Examples of different engine components or systems include, but are notlimited to: fuel injectors, spark plugs, electronically controlledvalves, a throttle, as well as other systems or components utilized forthe operation of engine 102.

It will be understood that only some components of motor vehicle 100 areshown in the current embodiment. In other embodiments, additionalcomponents could be included, while some of the components shown herecould be optional. Moreover, ECU 150 could include additional ports forcommunicating with various other systems, sensors or components of motorvehicle 100. As an example, in some cases, ECU 150 could be inelectrical communication with various sensors for detecting variousoperating parameters of motor vehicle 100, including but not limited to:vehicle speed, vehicle location, yaw rate, lateral g forces, fuel level,fuel composition, various diagnostic parameters as well as any othervehicle operating parameters and/or environmental parameters (such asambient temperature, pressure, elevation, etc.).

In some embodiments, ECU 150 can include provisions for communicatingwith and/or controlling various different vehicle systems. Vehiclesystems include any automatic or manual systems that may be used toenhance the driving experience and/or enhance safety. In one embodiment,ECU 150 can include port 157 for communicating with and/or controllingvehicle systems 172. For purposes of illustration, a single port isshown in the current embodiment for communicating with vehicle systems172. However, it will be understood that in some embodiments, more thanone port can be used. For example, in some cases, a separate port may beused for communicating with each separate vehicle system of vehiclesystems 172. Moreover, in embodiments where ECU 150 comprises part ofthe vehicle system, ECU 150 can include additional ports forcommunicating with and/or controlling various different components ordevices of a vehicle system. Examples of different vehicle systems 172are illustrated in FIG. 2. It should be understood that the systemsshown in FIG. 2 are only intended to be exemplary and in some cases someother additional systems may be included. In other cases, some of thesystems may be optional and not included in all embodiments.

Motor vehicle 100 can include electronic stability control system 222(also referred to as ESC system 222). ESC system 222 can includeprovisions for maintaining the stability of motor vehicle 100. In somecases, ESC system 222 may monitor the yaw rate and/or lateral gacceleration of motor vehicle 100 to help improve traction andstability. ESC system 222 may actuate one or more brakes automaticallyto help improve traction. An example of an electronic stability controlsystem is disclosed in Ellis et al., U.S. Pat. No. 8,423,257, theentirety of which is hereby incorporated by reference. In oneembodiment, the electronic stability control system may be a vehiclestability system.

In some embodiments, motor vehicle 100 can include antilock brake system224 (also referred to as ABS system 224). ABS system 224 can includevarious different components such as a speed sensor, a pump for applyingpressure to the brake lines, valves for removing pressure from the brakelines, and a controller. In some cases, a dedicated ABS controller maybe used. In other cases, ECU 150 can function as an ABS controller.Examples of antilock braking systems are known in the art. One exampleis disclosed in Ingaki, et al., U.S. Pat. No. 6,908,161, filed Nov. 18,2003, the entirety of which is hereby incorporated by reference. UsingABS system 224 may help improve traction in motor vehicle 100 bypreventing the wheels from locking up during braking.

Motor vehicle 100 can include brake assist system 226. Brake assistsystem 226 may be any system that helps to reduce the force required bya driver to depress a brake pedal. In some cases, brake assist system226 may be activated for older drivers or any other drivers who may needassistance with braking. An example of a brake assist system can befound in Wakabayashi et al., U.S. Pat. No. 6,309,029, filed Nov. 17,1999, the entirety of which is hereby incorporated by reference.

In some embodiments, motor vehicle 100 can include automatic brakeprefill system 228 (also referred to as ABP system 228). ABP system 228includes provisions for prefilling one or more brake lines with brakefluid prior to a collision. This may help increase the reaction time ofthe braking system as the driver depresses the brake pedal. Examples ofautomatic brake prefill systems are known in the art. One example isdisclosed in Bitz, U.S. Pat. No. 7,806,486, the entirety of which ishereby incorporated by reference.

In some embodiments, motor vehicle 100 can include low speed followsystem 230 (also referred to as LSF system 230). LSF system 230 includesprovisions for automatically following a preceding vehicle at a setdistance or range of distances. This may reduce the need for the driverto constantly press and depress the acceleration pedal in slow trafficsituations. LSF system 230 may include components for monitoring therelative position of a preceding vehicle (for example, using remotesensing devices such as lidar or radar). In some cases, LSF system 230may include provisions for communicating with any preceding vehicles fordetermining the GPS positions and/or speeds of the vehicles. Examples oflow speed follow systems are known in the art. One example is disclosedin Arai, U.S. Pat. No. 7,337,056, filed Mar. 23, 2005, the entirety ofwhich is hereby incorporated by reference. Another example is disclosedin Higashimata et al., U.S. Pat. No. 6,292,737, filed May 19, 2000, theentirety of which is hereby disclosed by reference.

Motor vehicle 100 can include cruise control system 232. Cruise controlsystems are well known in the art and allow a user to set a cruisingspeed that is automatically maintained by a vehicle control system. Forexample, while traveling on a highway, a driver may set the cruisingspeed to 55 mph. Cruise control system 232 may maintain the vehiclespeed at approximately 55 mph automatically, until the driver depressesthe brake pedal or otherwise deactivates the cruising function.

Motor vehicle 100 can include collision warning system 234. In somecases, collision warning system 234 may include provisions for warning adriver of any potential collision threats with one or more vehicles. Forexample, a collision warning system can warn a driver when anothervehicle is passing through an intersection as motor vehicle 100approaches the same intersection. Examples of collision warning systemsare disclosed in Mochizuki, U.S. Pat. No. 8,557,718, and Mochizuki etal., U.S. Pat. No. 8,587,418, the entirety of both being herebyincorporated by reference. In one embodiment, collision warning system234 could be a forward collision warning system.

Motor vehicle 100 can include collision mitigation braking system 236(also referred to as CMBS 236). CMBS 236 may include provisions formonitoring vehicle operating conditions (including target vehicles andobjects in the environment of the vehicle) and automatically applyingvarious stages of warning and/or control to mitigate collisions. Forexample, in some cases, CMBS 236 may monitor forward vehicles using aradar or other type of remote sensing device. If motor vehicle 100 getstoo close to a forward vehicle, CMBS 236 could enter a first warningstage. During the first warning stage, a visual and/or audible warningmay be provided to warn the driver. If motor vehicle 100 continues toget closer to the forward vehicle, CMBS 236 could enter a second warningstage. During the second warning stage, CMBS 236 could apply automaticseatbelt pretensioning. In some cases, visual and/or audible warningscould continue throughout the second warning stage. Moreover, in somecases, during the second stage automatic braking could also be activatedto help reduce the vehicle speed. In some cases, a third stage ofoperation for CMBS 236 may involve braking the vehicle and tightening aseatbelt automatically in situations where a collision is very likely.An example of such a system is disclosed in Bond, et al., U.S. Pat. No.6,607,255, and filed Jan. 17, 2002, the entirety of which is herebyincorporated by reference. The term collision mitigation braking systemas used throughout this detailed description and in the claims refers toany system that is capable of sensing potential collision threats andproviding various types of warning responses as well as automatedbraking in response to potential collisions.

Motor vehicle 100 can include auto cruise control system 238 (alsoreferred to as ACC system 238). In some cases, ACC system 238 mayinclude provisions for automatically controlling the vehicle to maintaina predetermined following distance behind a preceding vehicle or toprevent a vehicle from getting closer than a predetermined distance to apreceding vehicle. ACC system 238 may include components for monitoringthe relative position of a preceding vehicle (for example, using remotesensing devices such as lidar or radar). In some cases, ACC system 238may include provisions for communicating with any preceding vehicles fordetermining the GPS positions and/or speeds of the vehicles. An exampleof an auto cruise control system is disclosed in Arai et al., U.S. Pat.No. 7,280,903, filed Aug. 31, 2005, the entirety of which is herebyincorporated by reference.

Motor vehicle 100 can include lane departure warning system 240 (alsoreferred to as LDW system 240). LDW system 240 may determine when adriver is deviating from a lane and provide a warning signal to alertthe driver. Examples of lane departure warning systems can be found inTanida et al., U.S. Pat. No. 8,063,754, the entirety of which is herebyincorporated by reference.

Motor vehicle 100 can include blind spot indicator system 242. Blindspot indicator system 242 can include provisions for helping to monitorthe blind spot of a driver. In some cases, blind spot indicator system242 can include provisions to warn a driver if a vehicle is locatedwithin a blind spot. Any known systems for detecting objects travelingaround a vehicle can be used.

In some embodiments, motor vehicle 100 can include lane keep assistsystem 244. Lane keep assist system 244 can include provisions forhelping a driver to stay in the current lane. In some cases, lane keepassist system 244 can warn a driver if motor vehicle 100 isunintentionally drifting into another lane. Also, in some cases, lanekeep assist system 244 may provide assisting control to maintain avehicle in a predetermined lane. An example of a lane keep assist systemis disclosed in Nishikawa et al., U.S. Pat. No. 6,092,619, filed May 7,1997, the entirety of which is hereby incorporated by reference.

In some embodiments, motor vehicle 100 could include navigation system248. Navigation system 248 could be any system capable of receiving,sending and/or processing navigation information. The term “navigationinformation” refers to any information that can be used to assist indetermining a location or providing directions to a location. Someexamples of navigation information include street addresses, streetnames, street or address numbers, apartment or suite numbers,intersection information, points of interest, parks, any political orgeographical subdivision including town, township, province, prefecture,city, state, district, ZIP or postal code, and country. Navigationinformation can also include commercial information including businessand restaurant names, commercial districts, shopping centers, andparking facilities. In some cases, the navigation system could beintegrated into the motor vehicle. In other cases, the navigation systemcould be a portable or stand-alone navigation system.

Motor vehicle 100 can include climate control system 250. Climatecontrol system 250 may be any type of system used for controlling thetemperature or other ambient conditions in motor vehicle 100. In somecases, climate control system 250 may comprise a heating, ventilationand air conditioning system as well as an electronic controller foroperating the HVAC system. In some embodiments, climate control system250 can include a separate dedicated controller. In other embodiments,ECU 150 may function as a controller for climate control system 250. Anykind of climate control system known in the art may be used.

Motor vehicle 100 can include electronic pretensioning system 254 (alsoreferred to as EPT system 254). EPT system 254 may be used with aseatbelt for a vehicle. EPT system 254 can include provisions forautomatically tightening, or tensioning, the seatbelt. In some cases,EPT system 254 may automatically pretension the seatbelt prior to acollision. An example of an electronic pretensioning system is disclosedin Masuda et al., U.S. Pat. No. 6,164,700, filed Apr. 20, 1999, theentirety of which is hereby incorporated by reference.

Additionally, vehicle systems 172 could incorporate electronic powersteering system 160, visual devices 166, audio devices 168 and tactiledevices 170, as well as any other kinds of devices, components orsystems used with vehicles.

It will be understood that each of these vehicle systems may bestandalone systems or may be integrated with ECU 150. For example, insome cases, ECU 150 may operate as a controller for various componentsof one or more vehicle systems. In other cases, some systems maycomprise separate dedicated controllers that communicate with ECU 150through one or more ports.

FIG. 3 illustrates an embodiment of various autonomic monitoring systemsthat could be associated with motor vehicle 100. These autonomicmonitoring systems could include one or more bio-monitoring sensors 164.For example, in some embodiments, motor vehicle 100 could include heartmonitoring system 302. Heart monitoring system 302 could include anydevices or systems for monitoring the heart information of a driver. Insome cases, heart monitoring system 302 could include heart rate sensors320, blood pressure sensors 322 and oxygen content sensors 324 as wellas any other kinds of sensors for detecting heart information and/orcardiovascular information. Moreover, sensors for detecting heartinformation could be disposed in any locations within motor vehicle 100.For example, heart monitoring system 302 could include sensors disposedin a steering wheel, seat, armrest or other component that detect theheart information of a driver. Motor vehicle 100 could also includerespiratory monitoring system 304. Respiratory monitoring system 304could include any devices or systems for monitoring the respiratoryfunction (e.g. breathing) of a driver. For example, respiratorymonitoring system 304 could include sensors disposed in a seat fordetecting when a driver inhales and exhales. In some embodiments, motorvehicle 100 could include perspiration monitoring system 306.Perspiration monitoring system 306 may include any devices or systemsfor sensing perspiration or sweat from a driver. In some embodiments,motor vehicle 100 could include pupil dilation monitoring system 308 forsensing the amount of pupil dilation, or pupil size, in a driver. Insome cases, pupil dilation monitoring system 308 could include one ormore optical sensing devices.

Additionally, in some embodiments, motor vehicle 100 may include brainmonitoring system 310 for monitoring various kinds of brain information.In some cases, brain monitoring system 310 could includeelectroencephalogram (EEG) sensors 330, functional near infraredspectroscopy (fNIRS) sensors 332, functional magnetic resonance imaging(fMRI) sensors 334 as well as other kinds of sensors capable ofdetecting brain information. Such sensors could be located in anyportion of motor vehicle 100. In some cases, sensors associated withbrain monitoring system 310 could be disposed in a headrest. In othercases, sensors could be disposed in the roof of motor vehicle 100. Instill other cases, sensors could be disposed in any other locations.

In some embodiments, motor vehicle 100 may include digestion monitoringsystem 312. In other embodiments, motor vehicle 100 may includesalivation monitoring system 314. In some cases, monitoring digestionand/or salivation could also help in determining if a driver is drowsy.Sensors for monitoring digestion information and/or salivationinformation can be disposed in any portion of a vehicle. In some cases,sensors could be disposed on a portable device used or worn by a driver.

It will be understood that each of the monitoring systems discussedabove could be associated with one or more sensors or other devices. Insome cases, the sensors could be disposed in one or more portions ofmotor vehicle 100. For example, the sensors could be integrated into aseat, door, dashboard, steering wheel, center console, roof or any otherportion of motor vehicle 100. In other cases, however, the sensors couldbe portable sensors worn by a driver, integrated into a portable devicecarried by the driver or integrated into an article of clothing worn bythe driver.

For purposes of convenience, various components discussed above andshown in FIGS. 1 through 3 may be referred to as driver behaviorresponse system 199, also referred to simply as response system 199. Insome cases, response system 199 comprises ECU 150 as well as one or moresensors, components, devices or systems discussed above. In some cases,response system 199 may receive input from various devices related tothe behavior of a driver. In some cases, this information may bereferred to as “monitoring information”. In some cases, monitoringinformation could be received from a monitoring system, which mayinclude any system configured to provide monitoring information such asoptical devices, thermal devices, autonomic monitoring devices as wellas any other kinds of devices, sensors or systems. In some cases,monitoring information could be received directly from a vehicle system,rather than from a system or component designed for monitoring driverbehavior. In some cases, monitoring information could be received fromboth a monitoring system and a vehicle system. Response system 199 mayuse this information to modify the operation of one or more vehiclesystems 172. Moreover, it will be understood that in differentembodiments, response system 199 could be used to control any othercomponents or systems utilized for operating motor vehicle 100.

Response system 199 can include provisions for determining if a driveris drowsy based on biological information, including information relatedto the autonomic nervous system of the driver. For example, a responsesystem could detect a drowsy condition for a driver by analyzing heartinformation, breathing rate information, brain information, perspirationinformation as well as any other kinds of autonomic information.

A motor vehicle can include provisions for assessing the behavior of adriver and automatically adjusting the operation of one or more vehiclesystems in response to the behavior. Throughout this specification,drowsiness will be used as the example behavior being assessed; however,it should be understood that any driver behavior could be assessed,including but not limited to drowsy behavior, distracted behavior,impaired behavior and/or generally inattentive behavior. The assessmentand adjustment discussed below may accommodate for the driver's slowerreaction time, attention lapse and/or alertness. For example, insituations where a driver may be drowsy, the motor vehicle can includeprovisions for detecting that the driver is drowsy. Moreover, sincedrowsiness can increase the likelihood of hazardous driving situations,the motor vehicle can include provisions for modifying one or morevehicle systems automatically in order to mitigate against hazardousdriving situations. In one embodiment, a driver behavior response systemcan receive information about the state of a driver and automaticallyadjust the operation of one or more vehicle systems.

The following detailed description discusses a variety of differentmethods for operating vehicle systems in response to driver behavior. Indifferent embodiments, the various different steps of these processesmay be accomplished by one or more different systems, devices orcomponents. In some embodiments, some of the steps could be accomplishedby a response system 199 of a motor vehicle. In some cases, some of thesteps may be accomplished by an ECU 150 of a motor vehicle. In otherembodiments, some of the steps could be accomplished by other componentsof a motor vehicle, including but not limited to, the vehicle systems172. Moreover, for each process discussed below and illustrated in theFigures it will be understood that in some embodiments one or more ofthe steps could be optional.

FIG. 4 illustrates an embodiment of a process for controlling one ormore vehicle systems in a motor vehicle depending on the state of thedriver. In some embodiments, some of the following steps could beaccomplished by a response system 199 of a motor vehicle. In some cases,some of the following steps may be accomplished by an ECU 150 of a motorvehicle. In other embodiments, some of the following steps could beaccomplished by other components of a motor vehicle, such as vehiclesystems 172. In still other embodiments, some of the following stepscould be accomplished by any combination of systems or components of thevehicle. It will be understood that in some embodiments one or more ofthe following steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 402, response system 199 may receive monitoring information. Insome cases, the monitoring information can be received from one or moresensors. In other cases, the monitoring information can be received fromone or more autonomic monitoring systems. In still other cases, themonitoring information can be received from one or more vehicle systems.In still other cases, the monitoring information can be received fromany other device of motor vehicle 100. In still other cases, themonitoring information can be received from any combination of sensors,monitoring systems, vehicles systems or other devices.

In step 404, response system 199 may determine the driver state. In somecases, the driver state may be normal or drowsy. In other cases, thedriver state may range over three or more states ranging between normaland very drowsy (or even asleep). In this step, response system 199 mayuse any information received during step 402, including information fromany kinds of sensors or systems. For example, in one embodiment,response system 199 may receive information from an optical sensingdevice that indicates the driver has closed his or her eyes for asubstantial period of time. Other examples of determining the state of adriver are discussed in detail below.

In step 406, response system 199 may determine whether or not the driveris drowsy. If the driver is not drowsy, response system 199 may proceedback to step 402 to receive additional monitoring information. If,however, the driver is drowsy, response system 199 may proceed to step408. In step 408, response system 199 may automatically modify thecontrol of one or more vehicle systems, including any of the vehiclesystems discussed above. By automatically modifying the control of oneor more vehicle systems, response system 199 may help to avoid varioushazardous situations that can be caused by a drowsy driver.

In some embodiments, a user may not want any vehicle systems modified oradjusted. In these cases, the user may switch input device 111, or asimilar kind of input device, to the OFF position (see FIG. 1). Thiscould have the effect of turning off all body state monitoring and wouldfurther prevent response system 199 from modifying the control of anyvehicle systems. Moreover, response system 199 could be reactivated atany time by switching input device 111 to the ON position (see FIG. 1).In other embodiments, additional switches or buttons could be providedto turn on/off individual monitoring systems.

FIG. 5 is a table emphasizing the response system 199 impact on variousvehicle systems due to changes in the driver's behavior, as well as thebenefits to the driver for each change according to one embodiment. Inparticular, column 421 lists the various vehicle systems, which includemany of the vehicle systems 172 discussed above and shown in FIG. 2.Column 422 describes how response system 199 impacts the operation ofeach vehicle system when the driver's behavior is such that the drivermay be distracted, drowsy, less attentive and/or impaired. Column 423describes the benefits for the response system impacts described incolumn 422. Column 424 describes the type of impact performed byresponse system 199 for each vehicle system. In particular, in column424 the impact of response system 199 on each vehicle system isdescribed as either “control” type or “warning” type. The control typeindicates that the operation of a vehicle system is modified by thecontrol system. The warning type indicates that the vehicle system isused to warn or otherwise alert a driver.

As indicated in FIG. 5, upon detecting that a driver is drowsy orotherwise inattentive, response system 199 may control the electronicstability control system 222, the anti-lock brake system 224, the brakeassist system 226 and the brake pre-fill system 228 in a manner thatcompensates for the potentially slower reaction time of the driver. Forexample, in some cases, response system 199 may operate the electronicstability system 222 to improve steering precision and enhancestability. In some cases, response system 199 may operate the anti-lockbrake system 224 so that the stopping distance is decreased. In somecases, response system 199 may control the brake assist system 226 sothat an assisted braking force is applied sooner. In some cases,response system 199 may control the brake pre-fill system 228 so thebrake lines are automatically pre-filled with brake fluid when a driveris drowsy. These actions may help to improve the steering precision andbrake responsiveness when a driver is drowsy.

Additionally, upon detecting that a driver is drowsy or otherwiseinattentive, response system 199 may control the low speed follow system230, the cruise control system 232, the collision warning system 234,the collision mitigation braking system 236, the auto cruise controlsystem 238, the lane departure warning system 240, the blind spotindicator system 242 and the lane keep assist system 244 to provideprotection due to the driver's lapse of attention. For example, the lowspeed follow system 230, cruise control system 232 and lane keep assistsystem 244 could be disabled when the driver is drowsy to preventunintended use of these systems. Likewise, the collision warning system234, collision mitigation braking system 236, lane departure warningsystem 240 and blind spot indicator system 242 could warn a driversooner about possible potential hazards. In some cases, the auto cruisecontrol system 238 could be configured to increase the minimum gapdistance between motor vehicle 100 and the preceding vehicle.

In some embodiments, upon detecting that a driver is drowsy or otherwiseinattentive, response system 199 may control the electronic powersteering system 160, visual devices 166, the climate control system 250(such as HVAC), audio devices 168, the electronic pretensioning system254 for a seatbelt and tactile devices 170 to supplement the driver'salertness. For example, the electronic power steering system 160 may becontrolled to decrease power steering assistance. This requires thedriver to apply more effort and can help improve awareness or alertness.Visual devices 166 and audio devices 168 may be used to provide visualfeedback and audible feedback, respectively. Tactile devices 170 and theelectronic pretensioning system 254 can be used to provide tactilefeedback to a driver. Also, the climate control system 250 may be usedto change the cabin or driver temperature to effect the drowsiness ofthe driver. For example, by changing the cabin temperature the drivermay be made more alert.

The various systems listed in FIG. 5 are only intended to be exemplaryand other embodiments could include additional vehicle systems that maybe controlled by response system 199. Moreover, these systems are notlimited to a single impact or function. Also, these systems are notlimited to a single benefit. Instead, the impacts and benefits listedfor each system are intended as examples. A detailed explanation of thecontrol of many different vehicle systems is discussed in detail belowand shown in the Figures.

A response system can include provisions for determining a level ofdrowsiness for a driver. The term “level of drowsiness” as usedthroughout this detailed description and in the claims refers to anynumerical or other kind of value for distinguishing between two or morestates of drowsiness. For example, in some cases, the level ofdrowsiness may be given as a percentage between 0% and 100%, where 0%refers to a driver that is totally alert and 100% refers to a driverthat is fully drowsy or even asleep. In other cases, the level ofdrowsiness could be a value in the range between 1 and 10. In stillother cases, the level of drowsiness may not be a numerical value, butcould be associated with a given discrete state, such as “not drowsy”,“slightly drowsy”, “drowsy”, “very drowsy” and “extremely drowsy”.Moreover, the level of drowsiness could be a discrete value or acontinuous value. In some cases, the level of drowsiness may beassociated with a body state index, which is discussed in further detailbelow.

FIG. 6 illustrates an embodiment of a process of modifying the operationof a vehicle system according to the level of drowsiness detected. Insome embodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 442, response system 199 may receive monitoring information. Insome cases, the monitoring information can be received from one or moresensors. In other cases, the monitoring information can be received fromone or more autonomic monitoring systems. In still other cases, themonitoring information can be received from one or more vehicle systems.In still other cases, the monitoring information can be received fromany other device of motor vehicle 100. In still other cases, themonitoring information can be received from any combination of sensors,monitoring systems, vehicles systems or other devices.

In step 444, response system 199 may determine if the driver is drowsy.If the driver is not drowsy, response system 199 may return back to step

442. If the driver is drowsy, response system 199 may proceed to step446. In step 446, response system 199 may determine the level ofdrowsiness. As discussed above, the level of drowsiness could berepresented by a numerical value or could be a discrete state labeled bya name or variable. In step 448, response system 199 may modify thecontrol of one or more vehicle systems according to the level ofdrowsiness.

Examples of systems that can be modified according to the level ofdrowsiness include, but are not limited to: antilock brake system 224,automatic brake prefill system 228, brake assist system 226, auto cruisecontrol system 238, electronic stability control system 222, collisionwarning system 234, lane keep assist system 244, blind spot indicatorsystem 242, electronic pretensioning system 254 and climate controlsystem 250. In addition, electronic power steering system 160 could bemodified according to the level of drowsiness, as could visual devices166, audio devices 168 and tactile devices 170. In some embodiments, thetiming and/or intensity associated with various warning indicators(visual indicators, audible indicators, haptic indicators, etc.) couldbe modified according to the level of drowsiness. For example, in oneembodiment, electronic pretensioning system 254 could increase ordecrease the intensity and/or frequency of automatic seatbelt tighteningto warn the driver at a level appropriate for the level of drowsiness.

As an example, when a driver is extremely drowsy, the antilock brakesystem 224 may be modified to achieve a shorter stopping distance thanwhen a driver is somewhat drowsy. As another example, automatic brakeprefill system 228 could adjust the amount of brake fluid deliveredduring a prefill or the timing of the prefill according to the level ofdrowsiness. Likewise, the level of brake assistance provided by brakeassist system 226 could be varied according to the level of drowsiness,with assistance increased with drowsiness. Also, the headway distancefor auto cruise control system 238 could be increased with the level ofdrowsiness. In addition, the error between the yaw rate and the steeringyaw rate determined by electronic stability control system 222 could bedecreased in proportion to the level of drowsiness. In some cases,collision warning system 234 and lane departure system 240 could provideearlier warnings to a drowsy driver, where the timing of the warnings ismodified in proportion to the level of drowsiness. Likewise, thedetection area size associated with blind spot indicator system 242could be varied according to the level of drowsiness. In some cases, thestrength of a warning pulse generated by electronic pretensioning system254 may vary in proportion to the level of drowsiness. Also, climatecontrol system 250 may vary the number of degrees that the temperatureis changed according to the level of drowsiness. Moreover, thebrightness of the lights activated by visual devices 166 when a driveris drowsy could be varied in proportion to the level of drowsiness.Also, the volume of sound generated by audio devices 168 could be variedin proportion to the level of drowsiness. In addition, the amount ofvibration or tactile stimulation delivered by tactile devices 170 couldbe varied in proportion to the level of drowsiness. In some cases, themaximum speed at which low speed follow system 230 operates could bemodified according to the level of drowsiness. Likewise, the on/offsetting or the maximum speed at which cruise control system 232 can beset may be modified in proportion to the level of drowsiness.Additionally, the degree of power steering assistance provided byelectronic power steering system 160 could be varied in proportion tothe level of drowsiness. Also, the distance that the collisionmitigation braking system begins to brake can be lengthened or the lanekeep assist system could be modified so that the driver must providemore input to the system.

FIG. 7 illustrates an embodiment of a process of modifying the operationof a vehicle system according to the level of drowsiness detected. Insome embodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 452, response system 199 may receive monitoring information, asdiscussed above and with respect to step 442 of FIG. 6. In step 454,response system 199 can receive any kind of vehicle operatinginformation from one or more vehicle systems. The type of operatinginformation received during step 454 may vary according to the type ofvehicle system involved. For example, if the current process is used foroperating a brake assist system, the operating information received maybe brake pressure, vehicle speed and other operating parameters relatedto a brake assist system. As another example, if the current process isused for operating an electronic stability control system, the operationinformation may include yaw rate, wheel speed information, steeringangle, lateral G, longitudinal G, road friction information as well asany other information used for operating an electronic stability controlsystem.

Next, in step 456, response system 199 can determine a body state indexof the driver. The term “body state index” refers to a measure of thedrowsiness of a driver. In some cases, the body state index could begiven as a numerical value. In other cases, the body state index couldbe given as a non-numerical value. Moreover, the body state index mayrange from values associated with complete alertness to valuesassociated with extreme drowsiness or even a state in which the driveris asleep. In one embodiment, the body state index could take on thevalues 1, 2, 3 and 4, where 1 is the least drowsy and 4 is the mostdrowsy. In another embodiment, the body state index could take on valuesfrom 1-10.

Generally, the body state index of the driver can be determined usingany of the methods discussed throughout this detailed description fordetecting driver behavior as it relates to drowsiness. In particular,the level of drowsiness may be detected by sensing different degrees ofdriver behavior. For example, as discussed below, drowsiness in a drivermay be detected by sensing eyelid movement and/or head movement. In somecases, the degree of eyelid movement (the degree to which the eyes areopen or closed) or the degree of head movement (how tilted the head is)could be used to determine the body state index. In other cases, theautonomic monitoring systems could be used to determine the body stateindex. In still other cases, the vehicle systems could be used todetermine the body state index. For example, the degree of unusualsteering behavior or the degree of lane departures may indicate acertain body state index.

In step 458, response system 199 may determine a control parameter. Theterm “control parameter” as used throughout this detailed descriptionand in the claims refers to a parameter used by one or more vehiclesystems. In some cases, a control parameter may be an operatingparameter that is used to determine if a particular function should beactivated for a given vehicle system. For example, in situations wherean electronic stability control system is used, the control parametermay be a threshold error in the steering yaw rate that is used todetermine if stability control should be activated. As another example,in situations where automatic cruise control is used, the controlparameter may be a parameter used to determine if cruise control shouldbe automatically turned off. Further examples of control parameters arediscussed in detail below and include, but are not limited to: stabilitycontrol activation thresholds, brake assist activation thresholds, blindspot monitoring zone thresholds, time to collision thresholds, roadcrossing thresholds, lane keep assist system status, low speed followstatus, electronic power steering status, auto cruise control status aswell as other control parameters.

In some cases, a control parameter can be determined using vehiclesystem information as well as the body state index determined duringstep 456. In other cases, only the body state index may be used todetermine the control parameter. In still other cases, only the vehicleoperating information may be used to determine the control parameter.Following step 458, during step 460, response system 199 may operate avehicle system using the control parameter.

FIGS. 8 and 9 illustrate schematic views of a general method fordetermining a control parameter using the body state index of the driveras well as vehicle operating information. In particular, FIG. 8illustrates a schematic view of how the body state index can be used toretrieve a control coefficient. A control coefficient may be any valueused in determining a control parameter. In some cases, the controlcoefficient varies as a function of body state index and is used as aninput for calculating the control parameter. Examples of controlcoefficients include, but are not limited to: electronic stabilitycontrol system coefficients, brake assist coefficients, blind spot zonewarning coefficients, warning intensity coefficients, forward collisionwarning coefficients, lane departure warning coefficients and lane keepassist coefficients. Some systems may not use a control coefficient todetermine the control parameter. For example, in some cases, the controlparameter can be determined directly from the body state index.

In one embodiment, the value of the control coefficient 470 increasesfrom 0% to 25% as the body state index increases from 1 to 4. In somecases, the control coefficient may serve as a multiplicative factor forincreasing or decreasing the value of a control parameter. For example,in some cases when the body state index is 4, the control coefficientmay be used to increase the value of a control parameter by 25%. Inother embodiments, the control coefficient could vary in any othermanner. In some cases, the control coefficient could vary linearly as afunction of body state index. In other cases, the control coefficientcould vary in a nonlinear manner as a function of body state index. Instill other cases, the control coefficient could vary between two ormore discrete values as a function of body state index.

As seen in FIG. 9, calculation unit 480 receives control coefficient 482and vehicle operating information 484 as inputs. Calculation unit 480outputs control parameter 486. Vehicle operating information 484 caninclude any information necessary to calculate a control parameter. Forexample, in situations where the vehicle system is an electronicstability control system, the system may receive wheel speedinformation, steering angle information, roadway friction information,as well as other information necessary to calculate a control parameterthat is used to determine when stability control should be activated.Moreover, as discussed above, control coefficient 482 may be determinedfrom the body state index using, for example, a look-up table.Calculation unit 480 then considers both the vehicle operatinginformation and the control coefficient in calculating control parameter486.

It will be understood that calculation unit 480 is intended to be anygeneral algorithm or process used to determine one or more controlparameters. In some cases, calculation unit 480 may be associated withresponse system 199 and/or ECU 150. In other cases, however, calculationunit 480 could be associated with any other system or device of motorvehicle 100, including any of the vehicle systems discussed previously.

In some embodiments, a control parameter may be associated with a statusor state of a given vehicle system. FIG. 10 illustrates an embodiment ofa general relationship between the body state index of the driver andsystem status 490. The system shown here is general and could beassociated with any vehicle system. For low body state index (1 or 2),the system status is ON. However, if the body state index increases to 3or 4 the system status is turned OFF. In still other embodiments, acontrol parameter could be set to multiple different “states” accordingto the body state index. Using this arrangement, the state of a vehiclesystem can be modified according the body state index of a driver.

A response system can include provisions for detecting the state of adriver by monitoring the eyes of a driver. FIG. 11 illustrates aschematic view of a scenario in which response system 199 is capable ofmonitoring the state or behavior of a driver. Referring to FIG. 11, ECU150 may receive information from optical sensing device 162. In somecases, optical sensing device 162 may be a video camera that is mountedin the dashboard of motor vehicle 100. The information may comprise asequence of images 500 that can be analyzed to determine the state ofdriver 502. First image 510 shows driver 502 in a fully awake state,with eyes 520 wide open. However, second image 512 shows driver 502 in adrowsy state, with eyes 520 half open. Finally, third image 514 showsdriver 502 in a very drowsy state with eyes 520 fully closed. In someembodiments, response system 199 may be configured to analyze variousimages of driver 502. More specifically, response system 199 may analyzethe movement of eyes 520 to determine if a driver is in a normal stateor a drowsy state.

It will be understood that any type of algorithm known in the art foranalyzing eye movement from images can be used. In particular, any typeof algorithm that can recognize the eyes and determine the position ofthe eyelids between a closed and open position may be used. Examples ofsuch algorithms may include various pattern recognition algorithms knownin the art.

In other embodiments, thermal sensing device 163 can be used to senseeyelid movement. For example, as the eyelids move between opened andclosed positions, the amount of thermal radiation received at thermalsensing device 163 may vary. In other words, thermal sensing device 163can be configured to distinguish between various eyelid positions basedon variations in the detected temperature of the eyes.

FIG. 12 illustrates an embodiment of a process for detecting drowsinessby monitoring eye movement in the driver. In some embodiments, some ofthe following steps could be accomplished by a response system 199 of amotor vehicle. In some cases, some of the following steps may beaccomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 602, response system 199 may receive optical/thermalinformation. In some cases, optical information could be received from acamera or other optical sensing device. In other cases, thermalinformation could be received from a thermal sensing device. In stillother cases, both optical and thermal information could be received froma combination of optical and thermal devices.

In step 604, response system 199 may analyze eyelid movement. Bydetecting eyelid movement, response system 199 can determine if the eyesof a driver are open, closed or in a partially closed position. Theeyelid movement can be determined using either optical information orthermal information received during step 602. Moreover, as discussedabove, any type of software or algorithm can be used to determine eyelidmovement from the optical or thermal information. Although the currentembodiment comprises a step of analyzing eyelid movement, in otherembodiments the movement of the eyeballs could also be analyzed.

In step 606, response system 199 determines the body state index of thedriver according to the eyelid movement. The body state index may haveany value. In some cases, the value ranges between 1 and 4, with 1 beingthe least drowsy and 4 being the drowsiest state. In some cases, todetermine the body state index response system 199 determines if theeyes are closed or partially closed for extended periods. In order todistinguish drooping eyelids due to drowsiness from blinking, responsesystem 199 may use a threshold time that the eyelids are closed orpartially closed. If the eyes of the driver are closed or partiallyclosed for periods longer than the threshold time, response system 199may determine that this is due to drowsiness. In such cases, the drivermay be assigned a body state index that is greater than 1 to indicatethat the driver is drowsy. Moreover, response system 199 may assigndifferent body state index values for different degrees of eyelidmovement or eyelid closure.

In some embodiments, response system 199 may determine the body stateindex based on detecting a single instance of prolonged eyelid closureor partial eyelid closure. Of course, it may also be the case thatresponse system 199 analyzes eye movement over an interval of time andlooks at average eye movements.

A response system can include provisions for detecting the state of adriver by monitoring the head of a driver. FIG. 13 illustrates aschematic view of a scenario in which response system 199 is capable ofmonitoring the state or behavior of a driver. Referring to FIG. 13, ECU150 may receive information from optical sensing device 162. In somecases, optical sensing device 162 may be a video camera that is mountedin the dashboard of motor vehicle 100. In other cases, a thermal sensingdevice could be used. The information may comprise a sequence of images700 that can be analyzed to determine the state of driver 702. Firstimage 710 shows driver 702 in a fully awake state, with head 720 in anupright position. However, second image 712 shows driver 702 in a drowsystate, with head 720 leaning forward. Finally, third image 714 showsdriver 702 in a drowsier state with head 720 fully tilted forward. Insome embodiments, response system 199 may be configured to analyzevarious images of driver 702. More specifically, response system 199 mayanalyze the movement of head 720 to determine if a driver is in a normalstate or a drowsy state.

It will be understood that any type of algorithm known in the art foranalyzing head movement from images can be used. In particular, any typeof algorithm that can recognize the head and determine the position ofthe head may be used. Examples of such algorithms may include variouspattern recognition algorithms known in the art.

FIG. 14 illustrates an embodiment of a process for detecting drowsinessby monitoring head movement in the driver. In some embodiments, some ofthe following steps could be accomplished by a response system 199 of amotor vehicle. In some cases, some of the following steps may beaccomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 802, response system 199 may receive optical and/or thermalinformation. In some cases, optical information could be received from acamera or other optical sensing device. In other cases, thermalinformation could be received from a thermal sensing device. In stillother cases, both optical and thermal information could be received froma combination of optical and thermal devices.

In step 804, response system 199 may analyze head movement. By detectinghead movement, response system 199 can determine if a driver is leaningforward. The head movement can be determined using either opticalinformation or thermal information received during step 802. Moreover,as discussed above, any type of software or algorithm can be used todetermine head movement from the optical or thermal information.

In step 806, response system 199 determines the body state index of thedriver in response to the detected head movement. For example, in somecases, to determine the body state index of the driver, response system199 determines if the head is tilted in any direction for extendedperiods. In some cases, response system 199 may determine if the head istilting forward. In some cases, response system 199 may assign a bodystate index depending on the level of tilt and/or the time interval overwhich the head remains tilted. For example, if the head is tiltedforward for brief periods, the body state index may be assigned a valueof 2, to indicate that the driver is slightly drowsy. If the head istilted forward for a significant period of time, the body state indexmay be assigned a value of 4 to indicate that the driver is extremelydrowsy.

In some embodiments, response system 199 may determine the body stateindex based on detecting a single instance of a driver tilting his orher head forward. Of course, it may also be the case that responsesystem 199 analyzes head movement over an interval of time and looks ataverage head movements.

A response system can include provisions for detecting the state of adriver by monitoring the relative position of the driver's head withrespect to a headrest. FIG. 15 illustrates a schematic view of ascenario in which response system 199 is capable of monitoring the stateor behavior of a driver. Referring to FIG. 15, ECU 150 may receiveinformation from proximity sensor 134. In some cases, proximity sensor134 may be a capacitor. In other cases, proximity sensor 134 may be alaser based sensor. In still other cases, any other kind of proximitysensor known in the art could be used. Response system 199 may monitorthe distance between the driver's head and headrest 137. In particular,response system 199 may receive information from proximity sensor 134that can be used to determine the distance between the driver's head andheadrest 137. For example, a first configuration 131 shows driver 139 ina fully awake state, with head 138 disposed against headrest 137.However, second configuration 132 shows driver 139 in a somewhat drowsystate. In this case, head 138 has moved further away from headrest 137as the driver slumps forward slightly. A third configuration 133 showsdriver 139 in a fully drowsy state. In this case, head 138 is movedstill further away from headrest 137 as the driver is further slumpedover. In some embodiments, response system 199 may be configured toanalyze information related to the distance between the driver's head138 and headrest 137. Moreover, response system 199 can analyze headposition and/or movement (including tilting, slumping and/or bobbing) todetermine if driver 139 is in a normal state or a drowsy state.

It will be understood that any type of algorithm known in the art foranalyzing head distance and/or movement from proximity or distanceinformation can be used. In particular, any type of algorithm that candetermine the relative distance between a headrest and the driver's headcan be used. Also, any algorithms for analyzing changes in distance todetermine head motion could also be used. Examples of such algorithmsmay include various pattern recognition algorithms known in the art.

FIG. 16 illustrates an embodiment of a process for detecting drowsinessby monitoring the distance of the driver's head from a headrest. In someembodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 202, response system 199 may receive proximity information. Insome cases, proximity information could be received from a capacitor orlaser based sensor. In other cases, proximity information could bereceived from any other sensor. In step 204, response system 199 mayanalyze the distance of the head from a headrest. By determining thedistance between the driver's head and the head rest, response system199 can determine if a driver is leaning forward. Moreover, by analyzinghead distance over time, response system 199 can also detect motion ofthe head. The distance of the head from the headrest can be determinedusing any type of proximity information received during step 202.Moreover, as discussed above, any type of software or algorithm can beused to determine the distance of the head and/or head motioninformation.

In step 206, response system 199 determines the body state index of thedriver in response to the detected head distance and/or head motion. Forexample, in some cases, to determine the body state index of the driver,response system 199 determines if the head is leaning away from theheadrest for extended periods. In some cases, response system 199 maydetermine if the head is tilting forward. In some cases, response system199 may assign a body state index depending on the distance of the headfrom the head rest as well as from the time interval over which the headis located away from the headrest. For example, if the head is locatedaway from the headrest for brief periods, the body state index may beassigned a value of 2, to indicate that the driver is slightly drowsy.If the head is located away from the headrest for a significant periodof time, the body state index may be assigned a value of 4 to indicatethat the driver is extremely drowsy. It will be understood that in somecases, a system could be configured so that the alert state of thedriver is associated with a predetermined distance between the head andthe headrest. This predetermined distance could be a factory set valueor a value determined by monitoring a driver over time. Then, the bodystate index may be increased when the driver's head moves closer to theheadrest or further from the headrest with respect to the predetermineddistance. In other words, in some cases the system may recognize thatthe driver's head may tilt forward and/or backward as he or she getsdrowsy.

In some embodiments, response system 199 may determine the body stateindex based on detecting a single distance measurement between thedriver's head and a headrest. Of course, it may also be the case thatresponse system 199 analyzes the distance between the driver's head andthe headrest over an interval of time and uses average distances todetermine body state index.

In some other embodiments, response system 199 could detect the distancebetween the driver's head and any other reference location within thevehicle. For example, in some cases a proximity sensor could be locatedin a ceiling of the vehicle and response system 199 may detect thedistance of the driver's head with respect to the location of theproximity sensor. In other cases, a proximity sensor could be located inany other part of the vehicle. Moreover, in other embodiments, any otherportions of a driver could be monitored for determining if a driver isdrowsy or otherwise alert. For example, in still another embodiment, aproximity sensor could be used in the backrest of a seat to measure thedistance between the backrest and the back of the driver.

A response system can include provisions for detecting abnormal steeringby a driver for purposes of determining if a driver is drowsy. FIG. 17illustrates a schematic view of motor vehicle 100 being operated bydriver 902. In this situation, ECU 150 may receive information relatedto the steering angle or steering position as a function of time. Inaddition, ECU 150 could also receive information about the torqueapplied to a steering wheel as a function of time. In some cases, thesteering angle information or torque information can be received fromEPS system 160, which may include a steering angle sensor as well as atorque sensor. By analyzing the steering position or steering torqueover time, response system 199 can determine if the steering isinconsistent, which may indicate that the driver is drowsy.

FIG. 18 illustrates an embodiment of a process for detecting drowsinessby monitoring the steering behavior of a driver. In some embodiments,some of the following steps could be accomplished by a response system199 of a motor vehicle. In some cases, some of the following steps maybe accomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 1002, response system 199 may receive steering angleinformation. In some cases, the steering angle information may bereceived from EPS 160 or directly from a steering angle sensor. Next, instep 1004, response system 199 may analyze the steering angleinformation. In particular, response system 199 may look for patterns inthe steering angle as a function of time that suggest inconsistentsteering, which could indicate a drowsy driver. Any method of analyzingsteering information to determine if the steering is inconsistent can beused. Moreover, in some embodiments, response system 199 may receiveinformation from lane keep assist system 244 to determine if a driver issteering motor vehicle 100 outside of a current lane.

In step 1006, response system 199 may determine the body state index ofthe driver based on steering wheel movement. For example, if thesteering wheel movement is inconsistent, response system 199 may assigna body state index of 2 or greater to indicate that the driver isdrowsy.

A response system can include provisions for detecting abnormal drivingbehavior by monitoring lane departure information. FIG. 19 illustrates aschematic view of an embodiment of motor vehicle 100 being operated bydriver fig950. In this situation, ECU 150 may receive lane departureinformation. In some cases, the lane departure information can bereceived from LDW system 240. Lane departure information could includeany kind of information related to the position of a vehicle relative toone or more lanes, steering behavior, trajectory or any other kind ofinformation. In some cases, the lane departure information could beprocessed information analyzed by LDW system 240 that indicates somekind of lane departure behavior. By analyzing the lane departureinformation, response system 199 can determine if the driving behavioris inconsistent, which may indicate that the driver is drowsy. In someembodiments, whenever LDW system 240 issues a lane departure warning,response system 199 may determine that the driver is drowsy. Moreover,the level of drowsiness could be determined by the intensity of thewarning.

FIG. 20 illustrates an embodiment of a process for detecting drowsinessby monitoring lane departure information. In some embodiments, some ofthe following steps could be accomplished by a response system 199 of amotor vehicle. In some cases, some of the following steps may beaccomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 1020, response system 199 may receive lane departureinformation. In some cases, the lane departure information may bereceived from LWD system 240 or directly from some kind of sensor (suchas a steering angle sensor, or a relative position sensor). Next, instep 1022, response system 199 may analyze the lane departureinformation. Any method of analyzing lane departure information can beused.

In step 1024, response system 199 may determine the body state index ofthe driver based on lane departure information. For example, if thevehicle is drifting out of the current lane, response system 199 mayassign a body state index of 2 or greater to indicate that the driver isdrowsy. Likewise, if the lane departure information is a lane departurewarning from LDW system 240, response system 199 may assign a body stateindex of 2 or greater to indicate that the driver is drowsy. Using thisprocess, response system 199 can use information from one or morevehicle systems 172 to help determine if a driver is drowsy. This ispossible since drowsiness (or other types of inattentiveness) not onlymanifest as driver behaviors, but can also cause changes in theoperation of the vehicle, which may be monitored by the various vehiclesystems 172.

FIG. 21 illustrates a schematic view of an embodiment of motor vehicle100, in which response system 199 is capable of detecting respiratoryrate information. In particular, using bio-monitoring sensor 164, ECU150 may be able to determine the number of breaths per minute taken bydriver 1102. This information can be analyzed to determine if themeasured breaths per minute coincides with a normal state or a drowsystate. Breaths per minute is given as an example, any other autonomicinformation could also be monitored and used to determine this state.

FIG. 22 illustrates an embodiment of a process for detecting drowsinessby monitoring the autonomic information of a driver. In someembodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as the vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 1202, response system 199 may receive information related to theautonomic nervous system of the driver. In some cases, the informationcan be received from a sensor. The sensor could be associated with anyportion of motor vehicle 100 including a seat, armrest or any otherportion. Moreover, the sensor could be a portable sensor in some cases.

In step 1204, response system 199 may analyze the autonomic information.Generally, any method of analyzing autonomic information to determine ifa driver is drowsy could be used. It will be understood that the methodof analyzing the autonomic information may vary according to the type ofautonomic information being analyzed. In step 1206, response system 199may determine the body state index of the driver based on the analysisconducted during step 1204.

It will be understood that the methods discussed above for determiningthe body state index of a driver according to eye movement, headmovement, steering wheel movement and/or sensing autonomic informationare only intended to be exemplary and in other embodiments any othermethod of detecting the behavior of a driver, including behaviorsassociated with drowsiness, could be used. Moreover, it will beunderstood that in some embodiments multiple methods for detectingdriver behavior to determine a body state index could be usedsimultaneously.

A response system can include provisions for controlling one or morevehicle systems to help wake a drowsy driver. For example, a responsesystem could control various systems to stimulate a driver in some way(visually, orally, or through movement, for example). A response systemcould also change ambient conditions in a motor vehicle to help wake thedriver and thereby increase the driver's alertness.

FIGS. 23 and 24 illustrate a schematic view of a method of waking adriver by modifying the control of an electronic power steering system.Referring to FIG. 23, driver 1302 is drowsy. Response system 199 maydetect that driver 1302 is drowsy using any of the detection methodsmentioned previously or through any other detection methods. Duringnormal operation, EPS system 160 functions to assist a driver in turningsteering wheel 1304. However, in some situations, it may be beneficialto reduce this assistance. For example, as seen in FIG. 24, bydecreasing the power steering assistance, driver 1302 must put moreeffort into turning steering wheel 1304. This may have the effect ofwaking up driver 1302, since driver 1302 must now apply a greater forceto turn steering wheel 1304.

FIG. 25 illustrates an embodiment of a process for controlling powersteering assistance according to the detected level of drowsiness for adriver. In some embodiments, some of the following steps could beaccomplished by a response system 199 of a motor vehicle. In some cases,some of the following steps may be accomplished by an ECU 150 of a motorvehicle. In other embodiments, some of the following steps could beaccomplished by other components of a motor vehicle, such as vehiclesystems 172. In still other embodiments, some of the following stepscould be accomplished by any combination of systems or components of thevehicle. It will be understood that in some embodiments one or more ofthe following steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 1502, response system 199 may receive drowsiness information. Insome cases, the drowsiness information includes whether a driver is in anormal state or a drowsy state. Moreover, in some cases, the drowsinessinformation could include a value indicating the level of drowsiness,for example on a scale of 1 to 10, with 1 being the least drowsy and 10being the drowsiest.

In step 1504, response system 199 determines if the driver is drowsybased on the drowsiness information. If the driver is not drowsy,response system 199 returns back to step 1502. If the driver is drowsy,response system 199 proceeds to step 1506. In step 1506, steering wheelinformation may be received. In some cases, the steering wheelinformation can be received from EPS system 160. In other cases, thesteering wheel information can be received from a steering angle sensoror a steering torque sensor directly.

In step 1508, response system 199 may determine if the driver is turningthe steering wheel. If not, response system 199 returns to step 1502. Ifthe driver is turning the steering wheel, response system 199 proceedsto step 1510 where the power steering assistance is decreased. It willbe understood that in some embodiments, response system 199 may notcheck to see if the wheel is being turned before decreasing powersteering assistance.

FIG. 26 illustrates an embodiment of a detailed process for controllingpower steering assistance to a driver according to a body state index.In step 1520, response system 199 may receive steering information. Thesteering information can include any type of information includingsteering angle, steering torque, rotational speed, motor speed as wellas any other steering information related to a steering system and/or apower steering assistance system. In step 1522, response system 199 mayprovide power steering assistance to a driver. In some cases, responsesystem 199 provides power steering assistance in response to a driverrequest (for example, when a driver turns on a power steering function).In other cases, response system 199 automatically provides powersteering assistance according to vehicle conditions or otherinformation.

In step 1524, response system 199 may determine the body state index ofa driver using any of the methods discussed above for determining a bodystate index. Next, in step 1526, response system 199 may set a powersteering status corresponding to the amount of steering assistanceprovided by the electronic power steering system. For example, in somecases, the power steering status is associated with two states,including a “low” state and a “standard” state. In the “standard” state,power steering assistance is applied at a predetermined levelcorresponding to an amount of power steering assistance that improvesdrivability and helps increase the driving comfort of the user. In the“low” state, less steering assistance is provided, which requiresincreased steering effort by a driver. As indicated by look-up table1540, the power steering status may be selected according to the bodystate index. For example, if the body state index is 1 or 2(corresponding to no drowsiness or slight drowsiness), the powersteering status is set to the standard state. If, however, the bodystate index is 3 or 4 (corresponding to a drowsy condition of thedriver), the power steering status is set to the low state. It will beunderstood that look-up table 1540 is only intended to be exemplary andin other embodiments the relationship between body state index and powersteering status can vary in any manner.

Once the power steering status is set in step 1526, response system 199proceeds to step 1528. In step 1528, response system 199 determines ifthe power steering status is set to low. If not, response system 199 mayreturn to step 1520 and continue operating power steering assistance atthe current level. However, if response system 199 determines that thepower steering status is set to low, response system 199 may proceed tostep 1530. In step 1530, response system 199 may ramp down powersteering assistance. For example, if the power steering assistance issupplying a predetermined amount of torque assistance, the powersteering assistance may be varied to reduce the assisting torque. Thisrequires the driver to increase steering effort. For a drowsy driver,the increased effort required to turn the steering wheel may helpincrease his or her alertness and improve vehicle handling.

In some cases, during step 1532, response system 199 may provide awarning to the driver of the decreased power steering assistance. Forexample, in some cases, a dashboard light reading “power steering off”or “power steering decreased” could be turned on. In other cases, anavigation screen or other display screen associated with the vehiclecould display a message indicating the decreased power steeringassistance. In still other cases, an audible or haptic indicator couldbe used to alert the driver. This helps to inform the driver of thechange in power steering assistance so the driver does not becomeconcerned of a power steering failure.

FIGS. 27 and 28 illustrate schematic views of a method of helping towake a drowsy driver by automatically modifying the operation of aclimate control system. Referring to FIG. 27, climate control system 250has been set to maintain a temperature of 75 degrees Fahrenheit insidethe cabin of motor vehicle 100 by driver 1602. This is indicated ondisplay screen 1620. As response system 199 detects that driver 1602 isbecoming drowsy, response system 199 may automatically change thetemperature of climate control system 250. As seen in FIG. 28, responsesystem 199 automatically adjusts the temperature to 60 degreesFahrenheit. As the temperature inside motor vehicle 100 cools down,driver 1602 may become less drowsy, which helps driver 1602 to be morealert while driving. In other embodiments, the temperature may beincreased in order to make the driver more alert.

FIG. 29 illustrates an embodiment of a process for helping to wake adriver by controlling the temperature in a vehicle. In some embodiments,some of the following steps could be accomplished by a response system199 of a motor vehicle. In some cases, some of the following steps maybe accomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 1802, response system 199 may receive drowsiness information. Instep 1804, response system 199 determines if the driver is drowsy. Ifthe driver is not drowsy, response system 199 proceeds back to step1802. If the driver is drowsy, response system 199 proceeds to step1806. In step 1806, response system 199 automatically adjusts the cabintemperature. In some cases, response system 199 may lower the cabintemperature by engaging a fan or air-conditioner. However, in some othercases, response system 199 could increase the cabin temperature using afan or heater. Moreover, it will be understood that the embodiments arenot limited to changing temperature and in other embodiments otheraspects of the in-cabin climate could be changed, including airflow,humidity, pressure or other ambient conditions. For example, in somecases, a response system could automatically increase the airflow intothe cabin, which may stimulate the driver and help reduce drowsiness.

FIGS. 30 and 31 illustrate schematic views of methods of alerting adrowsy driver using visual, audible and tactile feedback for a driver.Referring to FIG. 30, driver 1902 is drowsy as motor vehicle 100 ismoving. Once response system 199 detects this drowsy state, responsesystem 199 may activate one or more feedback mechanisms to help wakedriver 1902. Referring to FIG. 31, three different methods of waking adriver are shown. In particular, response system 199 may control one ormore tactile devices 170. Examples of tactile devices include vibratingdevices (such as a vibrating seat or massaging seat) or devices whosesurface properties can be modified (for example, by heating or coolingor by adjusting the rigidity of a surface). In one embodiment, responsesystem 199 may operate driver seat 190 to shake or vibrate. This mayhave the effect of waking driver 1902. In other cases, steering wheel2002 could be made to vibrate or shake. In addition, in some cases,response system 199 could activate one or more lights or other visualindicators. For example, in one embodiment, a warning may be displayedon display screen 2004. In one example, the warning may be “Wake!” andmay include a brightly lit screen to catch the driver's attention. Inother cases, overhead lights or other visual indicators could be turnedon to help wake the driver. In some embodiments, response system 199could generate various sounds through speakers 2010. For example, insome cases, response system 199 could activate a radio, CD player, MP3player or other audio device to play music or other sounds throughspeakers 2010. In other cases, response system 199 could play variousrecordings stored in memory, such as voices that tell a driver to wake.

FIG. 32 illustrates an embodiment of a process for waking up a driverusing various visual, audible and tactile stimuli. In some embodiments,some of the following steps could be accomplished by a response system199 of a motor vehicle. In some cases, some of the following steps maybe accomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 2102, response system 199 may receive drowsiness information. Instep 2104, response system 199 determines if the driver is drowsy. Ifthe driver is not drowsy, response system 199 returns to step 2102.Otherwise, response system 199 proceeds to step 2106. In step 2106,response system 199 may provide tactile stimuli to the driver. Forexample, response system 199 could control a seat or other portion ofmotor vehicle 100 to shake and/or vibrate (for example, a steeringwheel). In other cases, response system 199 could vary the rigidity of aseat or other surface in motor vehicle 100.

In step 2108, response system 199 may turn on one or more lights orindicators. The lights could be any lights associated with motor vehicle100 including dashboard lights, roof lights or any other lights. In somecases, response system 199 may provide a brightly lit message orbackground on a display screen, such as a navigation system displayscreen or climate control display screen. In step 2110, response system199 may generate various sounds using speakers in motor vehicle 100. Thesounds could be spoken words, music, alarms or any other kinds ofsounds. Moreover, the volume level of the sounds could be chosen toensure the driver is put in an alert state by the sounds, but not soloud as to cause great discomfort to the driver.

A response system can include provisions for controlling a seatbeltsystem to help wake a driver. In some cases, a response system cancontrol an electronic pretensioning system for a seatbelt to provide awarning pulse to a driver.

FIGS. 33 and 34 illustrate schematic views of an embodiment of aresponse system controlling an electronic pretensioning system for aseatbelt. Referring to FIGS. 33 and 34, as driver 2202 begins to feeldrowsy, response system 199 may automatically control EPT system 254 toprovide a warning pulse to driver 2202. In particular, seatbelt 2210 maybe initially loose as seen in FIG. 33, but as driver 2202 gets drowsy,seatbelt 2210 is pulled taut against driver 2202 for a moment as seen inFIG. 34. This momentary tightening serves as a warning pulse that helpsto wake driver 2202.

FIG. 35 illustrates an embodiment of a process for controlling EPTsystem 254. During step 2402, response system 199 receives drowsinessinformation. During step 2404, response system 199 determines if thedriver is drowsy. If the driver is not drowsy, response system 199returns to step 2402. If the driver is drowsy, response system 199proceeds to step 2406 where a warning pulse is sent. In particular, theseatbelt may be tightened to help wake or alert the driver.

A motor vehicle can include provisions for adjusting various brakecontrol systems according to the behavior of a driver. For example, aresponse system can modify the control of antilock brakes, brake assist,brake prefill as well as other braking systems when a driver is drowsy.This arrangement helps to increase the effectiveness of the brakingsystem in hazardous driving situations that may result when a driver isdrowsy.

FIGS. 36 and 37 illustrate schematic views of the operation of anantilock braking system. Referring to FIG. 36, when driver 2502 is fullyawake, ABS system 224 may be associated with first stopping distance2520. In particular, for a particular initial speed 2540, as driver 2502depresses brake pedal 2530, motor vehicle 100 may travel to firststopping distance 2520 before coming to a complete stop. This firststopping distance 2520 may be the result of various operating parametersof ABS system 224.

Referring now to FIG. 37, as driver 2502 becomes drowsy, response system199 may modify the control of ABS system 224. In particular, in somecases, one or more operating parameters of ABS system 224 may be changedto decrease the stopping distance. In this case, as driver 2502depresses brake pedal 2530, motor vehicle 100 may travel to secondstopping distance 2620 before coming to a complete stop. In oneembodiment, second stopping distance 2620 may be substantially shorterthan first stopping distance 2520. In other words, the stopping distancemay be decreased when driver 2502 is drowsy. Since a drowsy driver mayengage the brake pedal later due to a reduced awareness, the ability ofresponse system 199 to decrease the stopping distance may helpcompensate for the reduced reaction time of the driver. In anotherembodiment, if the vehicle is on a slippery surface the reduction instopping may not occur and instead tactile feedback may be appliedthrough the brake pedal.

FIG. 38 illustrates an embodiment of a process for modifying the controlof an antilock braking system according to the behavior of a driver. Insome embodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 2702, response system 199 may receive drowsiness information. Instep 2704, response system 199 may determine if the driver is drowsy. Ifthe driver is not drowsy, response system 199 returns to step 2702. Ifthe driver is drowsy, response system 199 may proceed to step 2706. Instep 2706, response system 199 may determine the current stoppingdistance. The current stopping distance may be a function of the currentvehicle speed, as well as other operating parameters including variousparameters associated with the brake system. In step 2708, responsesystem 199 may automatically decrease the stopping distance. This may beachieved by modifying one or more operating parameters of ABS system224. For example, the brake line pressure can be modified by controllingvarious valves, pumps and/or motors within ABS system 224.

In some embodiments, a response system can automatically prefill one ormore brake lines in a motor vehicle in response to driver behavior. FIG.39 illustrates an embodiment of a process for controlling brake lines ina motor vehicle in response to driver behavior. In some embodiments,some of the following steps could be accomplished by a response system199 of a motor vehicle. In some cases, some of the following steps maybe accomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 2802, response system 199 may receive drowsiness information. Instep 2804, response system 199 may determine if the driver is drowsy. Ifthe driver is not drowsy, response system 199 may return to step 2802.If the driver is drowsy, response system 199 may automatically prefillthe brake lines with brake fluid in step 2806. For example, responsesystem 199 may use automatic brake prefill system 228. In some cases,this may help increase braking response if a hazardous condition ariseswhile the driver is drowsy. It will be understood that any number ofbrake lines could be prefilled during step 2806. Moreover, anyprovisions known in the art for prefilling brake lines could be usedincluding any pumps, valves, motors or other devices needed to supplybrake fluid automatically to brake lines.

Some vehicles may be equipped with brake assist systems that help reducethe amount of force a driver must apply to engage the brakes. Thesesystems may be activated for older drivers or any other drivers who mayneed assistance with braking. In some cases, a response system couldutilize the brake assist systems when a driver is drowsy, since a drowsydriver may not be able to apply the necessary force to the brake pedalfor stopping a vehicle quickly.

FIG. 40 illustrates an embodiment of a method for controlling automaticbrake assist in response to driver behavior. In step 2902, responsesystem 199 may receive drowsiness information. In step 2904, responsesystem 199 may determine if the driver is drowsy. If the driver is notdrowsy, response system 199 proceeds back to step 2902. If the driver isdrowsy, response system 199 may determine if brake assist system 226 isalready on in step 2906. If brake assist system 226 is already on,response system 199 may return to step 2902. If brake assist system 226is not currently active, response system 199 may turn on brake assistsystem 226 in step 2908. This arrangement allows for braking assistanceto a drowsy driver, since the driver may not have sufficient ability tosupply the necessary braking force in the event that motor vehicle 100must be stopped quickly.

In some embodiments, a response system could modify the degree ofassistance in a brake assist system. For example, a brake assist systemmay operate under normal conditions with a predetermined activationthreshold. The activation threshold may be associated with the rate ofchange of the master cylinder brake pressure. If the rate of change ofthe master cylinder brake pressure exceeds the activation threshold,brake assist may be activated. However, when a driver is drowsy, thebrake assist system may modify the activation threshold so that brakeassist is activated sooner. In some cases, the activation thresholdcould vary according to the degree of drowsiness. For example, if thedriver is only slightly drowsy, the activation threshold may be higherthan when the driver is extremely drowsy.

FIG. 41 illustrates an embodiment of a detailed process for controllingautomatic brake assist in response to driver behavior. In particular,FIG. 41 illustrates a method in which brake assist is modified accordingto the body state index of the driver. In step 2930, response system 199may receive braking information. Braking information can includeinformation from any sensors and/or vehicle systems. In step 2932,response system 199 may determine if a brake pedal is depressed. In somecases, response system 199 may receive information that a brake switchhas been applied to determine if the driver is currently braking. Inother cases, any other vehicle information can be monitored to determineif the brakes are being applied. In step 2934, response system 199 maymeasure the rate of brake pressure increase. In other words, responsesystem 199 determines how fast the brake pressure is increasing, or how“hard” the brake pedal is being depressed. In step 2936, response system199 sets an activation threshold. The activation threshold correspondsto a threshold for the rate of brake pressure increase. Details of thisstep are discussed in detail below.

In step 2938, response system 199 determines if the rate of brakepressure increase exceeds the activation threshold. If not, responsesystem 199 proceeds back to step 2930. Otherwise, response system 199proceeds to step 2940. In step 2940, response system 199 activates amodulator pump and/or valves to automatically increase the brakepressure. In other words, in step 2940, response system 199 activatesbrake assist. This allows for an increase in the amount of braking forceapplied at the wheels.

FIG. 42 illustrates an embodiment of a process of selecting theactivation threshold discussed above. In some embodiments, the processshown in FIG. 42 corresponds to step 2936 of FIG. 41. In step 2950,response system 199 may receive the brake pressure rate and vehiclespeed as well as any other operating information. The brake pressurerate and vehicle speed correspond to current vehicle conditions that maybe used for determining an activation threshold under normal operatingconditions. In step 2952, an initial threshold setting may be determinedaccording to the vehicle operating conditions.

In order to accommodate changes in brake assist due to drowsiness, theinitial threshold setting may be modified according to the state of thedriver. In step 2954, response system 199 determines the body stateindex of the driver using any method discussed above. Next, in step2956, response system 199 determines a brake assist coefficient. As seenin look-up table 2960, the brake assist coefficient may vary between 0%and 25% according to the body state index. Moreover, the brake assistcoefficient generally increases as the body state index increases. Instep 2958, the activation threshold is selected according to the initialthreshold setting and the brake assist coefficient. If the brake assistcoefficient has a value of 0%, the activation threshold is just equal tothe initial threshold setting. However, if the brake assist coefficienthas a value of 25%, the activation threshold may be modified by up to25% in order to increase the sensitivity of the brake assist when thedriver is drowsy. In some cases, the activation threshold may beincreased by up to 25% (or any other amount corresponding to the brakeassist coefficient). In other cases, the activation threshold may bedecreased by up to 25% (or any other amount corresponding to the brakeassist coefficient).

A motor vehicle can include provisions for increasing vehicle stabilitywhen a driver is drowsy. In some cases, a response system can modify theoperation of an electronic stability control system. For example, insome cases, a response system could ensure that a detected yaw rate anda steering yaw rate (the yaw rate estimated from steering information)are very close to one another. This can help enhance steering precisionand reduce the likelihood of hazardous driving conditions while thedriver is drowsy.

FIGS. 43 and 44 are schematic views of an embodiment of motor vehicle100 turning around a curve in roadway 3000. Referring to FIG. 43, driver3002 is wide awake and turning steering wheel 3004. Also shown in FIG.43 are the driver intended path 3006 and the actual vehicle path 3008.The driver intended path may be determined from steering wheelinformation, yaw rate information, lateral g information as well asother kinds of operating information. The driver intended pathrepresents the ideal path of the vehicle, given the steering input fromthe driver. However, due to variations in road traction as well as otherconditions, the actual vehicle path may vary slightly from the driverintended path. Referring to FIG. 44, as driver 3002 gets drowsy,response system 199 modifies the operation of electronic stabilitycontrol system 222. In particular, ESC system 222 is modified so thatthe actual vehicle path 3104 is closer to the driver intended path 3006.This helps to minimize the difference between the driver intended pathand the actual vehicle path when the driver is drowsy, which can helpimprove driving precision.

FIG. 45 illustrates an embodiment of a process for controlling anelectronic vehicle stability system according to driver behavior. Insome embodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 3202, response system 199 may receive drowsiness information. Instep 3204, response system 199 determines if the driver is drowsy. Ifthe driver is not drowsy, response system 199 may return to step 3202.Otherwise, response system 199 receives yaw rate information in step3206. The yaw rate information could be received from a yaw rate sensorin some cases. In step 3208, response system 199 receives steeringinformation. This could include, for example, the steering wheel anglereceived from a steering angle sensor. In step 3210, response system 199determines the steering yaw rate using the steering information. In somecases, additional operating information could be used to determine thesteering yaw rate. In step 3212, response system 199 may reduce theallowable error between the measured yaw rate and the steering yaw rate.In other words, response system 199 helps minimize the differencebetween the driver intended path and the actual vehicle path.

In order to reduce the allowable error between the yaw rate and thesteering yaw rate, response system 199 may apply braking to one or morebrakes of motor vehicle 100 in order to maintain motor vehicle 100 closeto the driver intended path. Examples of maintaining a vehicle close toa driver intended path can be found in Ellis et al., U.S. Pat. No.8,423,257, the entirety of which is hereby incorporated by reference.

FIG. 46 illustrates an embodiment of a process for controlling anelectronic stability control system in response to driver behavior. Inparticular, FIG. 46 illustrates an embodiment in which the operation ofthe electronic stability control system is modified according to thebody state index of the driver. In step 3238, response system 199receives operating information. This information can include anyoperating information such as yaw rate, wheel speed, steering angles, aswell as other information used by an electronic stability controlsystem. In step 3240, response system 199 may determine if the vehiclebehavior is stable. In particular, in step 3242, response system 199measures the stability error of steering associated with under-steeringor over-steering. In some cases, the stability is determined bycomparing the actual path of the vehicle with the driver intended path.

In step 3244, response system 199 sets an activation thresholdassociated with the electronic stability control system. The activationthreshold may be associated with a predetermined stability error. Instep 3246, response system 199 determines if the stability error exceedsthe activation threshold. If not, response system 199 may return to step3238. Otherwise, response system 199 may proceed to step 3248. In step3248, response system 199 applies individual wheel brake control inorder to increase vehicle stability. In some embodiments, responsesystem 199 could also control the engine to apply engine braking ormodify cylinder operation in order to help stabilize the vehicle.

In some cases, in step 3250, response system 199 may activate a warningindicator. The warning indicator could be any dashboard light or messagedisplayed on a navigation screen or other video screen. The warningindicator helps to alert a driver that the electronic stability controlsystem has been activated. In some cases, the warning could be anaudible warning and/or a haptic warning.

FIG. 47 illustrates an embodiment of a process for setting theactivation threshold used in the previous method. In step 3260, responsesystem 199 receives vehicle operating information. For example, thevehicle operating information can include wheel speed information, roadsurface conditions (such as curvature, friction coefficients, etc.),vehicle speed, steering angle, yaw rate as well as other operatinginformation. In step 3262, response system 199 determines an initialthreshold setting according to the operating information received instep 3260. In step 3264, response system 199 determines the body stateindex of the driver.

In step 3266, response system 199 determines a stability controlcoefficient. As seen in look-up table 3270, the stability controlcoefficient may be determined from the body state index. In one example,the stability control coefficient ranges from 0% to 25%. Moreover, thestability control coefficient generally increases with the body stateindex. For example, if the body state index is 1, the stability controlcoefficient is 0%. If the body state index is 4, the stability controlcoefficient is 25%. It will be understood that these ranges for thestability control coefficient are only intended to be exemplary and inother cases the stability control coefficient could vary in any othermanner as a function of the body state index.

In step 3268, response system 199 may set the activation threshold usingthe initial threshold setting and the stability control coefficient. Forexample, if the stability control coefficient has a value of 25%, theactivation threshold may be up to 25% larger than the initial thresholdsetting. In other cases, the activation threshold may be up to 25%smaller than the initial threshold setting. In other words, theactivation threshold may be increased or decreased from the initialthreshold setting in proportion to the value of the stability controlcoefficient. This arrangement helps to increase the sensitivity of theelectronic stability control system by modifying the activationthreshold in proportion to the state of the driver.

FIG. 48 illustrates a schematic view of motor vehicle 100 equipped witha collision warning system 234. Collision warning system 234 canfunction to provide warnings about potential collisions to a driver. Forpurposes of clarity, the term “host vehicle” as used throughout thisdetailed description and in the claims refers to any vehicle including aresponse system while the term “target vehicle” refers to any vehiclemonitored by, or otherwise in communication with, a host vehicle. In thecurrent embodiment, for example, motor vehicle 100 may be a hostvehicle. In this example, as motor vehicle 100 approaches intersection3300 while target vehicle 3302 passes through intersection 3300,collision warning system 234 may provide warning alert 3310 on displayscreen 3320. Further examples of collision warning systems are disclosedin Mochizuki, U.S. Pat. No. 8,558,718, and Mochizuki et al., U.S. Pat.No. 8,587,418, the entirety of both being hereby incorporated byreference.

FIG. 49 illustrates an embodiment of a process for modifying a collisionwarning system according to driver behavior. In some embodiments, someof the following steps could be accomplished by a response system 199 ofa motor vehicle. In some cases, some of the following steps may beaccomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 3402, response system 199 may receive drowsiness information. Instep 3404, response system 199 may determine if the driver is drowsy. Ifthe driver is not drowsy, response system 199 may proceed back to step3402. Otherwise, response system 199 may proceed to step 3406. In step3406, response system 199 may modify the operation of a collisionwarning system so that the driver is warned earlier about potentialcollisions. For example, if the collision warning system was initiallyset to warn a driver about a potential collision if the distance to thecollision point is less than 25 meters, response system 199 could modifythe system to warn the driver if the distance to the collision point isless than 50 meters.

FIG. 50 illustrates an embodiment of a process for modifying a collisionwarning system according to driver behavior. In some embodiments, someof the following steps could be accomplished by a response system 199 ofa motor vehicle. In some cases, some of the following steps may beaccomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 3502, collision warning system 234 may retrieve the heading,position and speed of an approaching vehicle. In some cases, thisinformation could be received from the approaching vehicle through awireless network, such as a DSRC network. In other cases, thisinformation could be remotely sensed using radar, laser or other remotesensing devices.

In step 3504, collision warning system 234 may estimate a vehiclecollision point. The vehicle collision point is the location of apotential collision between motor vehicle 100 and the approachingvehicle, which could be traveling in any direction relative to motorvehicle 100. In some cases, in step 3504, collision warning system 234may use information about the position, heading and speed of motorvehicle 100 to calculate the vehicle collision point. In someembodiments, this information could be received from a GPS receiver thatis in communication with collision warning system 234 or response system199. In other embodiments, the vehicle speed could be received from avehicle speed sensor.

In step 3506, collision warning system 234 may calculate the distanceand/or time to the vehicle collision point. In particular, to determinethe distance, collision warning system 234 may calculate the differencebetween the vehicle collision point and the current location of motorvehicle 100. Likewise, to determine the time to collision warning system234 could calculate the amount of time it will take to reach the vehiclecollision point.

In step 3508, collision warning system 234 may receive drowsinessinformation from response system 199, or any other system or components.In step 3509, collision warning system 234 may determine if the driveris drowsy. If the driver is not drowsy, collision warning system 234 mayproceed to step 3510, where a first threshold parameter is retrieved. Ifthe driver is drowsy, collision warning system 234 may proceed to step3512, where a second threshold distance is retrieved. The firstthreshold parameter and the second threshold parameter could be eithertime thresholds or distance thresholds, according to whether the time tocollision or distance to collision was determined during step 3506. Insome cases, where both time and distance to the collision point areused, the first threshold parameter and the second threshold parametercan each comprise both a distance threshold and a time threshold.Moreover, it will be understood that the first threshold parameter andthe second threshold parameter may be substantially different thresholdsin order to provide a different operating configuration for collisionwarning system 234 according to whether the driver is drowsy or notdrowsy. Following both step 3510 and 3512, collision warning system 234proceeds to step 3514. In step 3514, collision warning system 234determines if the current distance and/or time to the collision point isless than the threshold parameter selected during the previous step(either the first threshold parameter or the second thresholdparameter).

The first threshold parameter and the second threshold parameter couldhave any values. In some cases, the first threshold parameter may beless than the second threshold parameter. In particular, if the driveris drowsy, it may be beneficial to use a lower threshold parameter,since this corresponds to warning a driver earlier about a potentialcollision. If the current distance or time is less than the thresholddistance or time (the threshold parameter), collision warning system 234may warn the driver in step 3516. Otherwise, collision warning system234 may not warn the driver in step 3518.

A response system can include provisions for modifying the operation ofan auto cruise control system according to driver behavior. In someembodiments, a response system can change the headway distanceassociated with an auto cruise control system. In some cases, theheadway distance is the closest distance a motor vehicle can get to apreceding vehicle. If the auto cruise control system detects that themotor vehicle is closer than the headway distance, the system may warnthe driver and/or automatically slow the vehicle to increase the headwaydistance.

FIGS. 51 and 52 illustrate schematic views of motor vehicle 100 cruisingbehind preceding vehicle 3602. In this situation, auto cruise controlsystem 238 is operating to automatically maintain a predeterminedheadway distance behind preceding vehicle 3602. When driver 3600 isawake, auto cruise control system 238 uses a first headway distance3610, as seen in FIG. 51. In other words, auto cruise control system 238automatically prevents vehicle 100 from getting closer than firstheadway distance 3610 to preceding vehicle 3602. As driver 3600 becomesdrowsy, as seen in FIG. 52, response system 199 may modify the operationof auto cruise control system 238 so that auto cruise control system 238increases the headway distance to second headway distance 3710. Secondheadway distance 3710 may be substantially larger than first headwaydistance 3610, since the reaction time of driver 3600 may be reducedwhen driver 3600 is drowsy.

FIG. 53 illustrates an embodiment of a method of modifying the controlof an auto cruise control system according to driver behavior. In someembodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 3802, response system 199 may receive drowsiness information. Instep 3804, response system 199 may determine if the driver is drowsy. Ifthe driver is not drowsy, response system 199 may return to step 3802.If the driver is drowsy, response system 199 may proceed to step 3806.In step 3806, response system 199 may determine if auto cruise controlis being used. If not, response system 199 may return back to step 3802.If auto cruise control is being used, response system 199 may proceed tostep 3808. In step 3808, response system 199 may retrieve the currentheadway distance for auto cruise control. In step 3810, response system199 may increase the headway distance. With this arrangement, responsesystem 199 may help increase the distance between motor vehicle 100 andother vehicles when a driver is drowsy to reduce the chances of ahazardous driving situation while the driver is drowsy.

FIG. 54 illustrates an embodiment of a process for controlling automaticcruise control in response to driver behavior. This embodiment couldalso apply to normal cruise control systems. In particular, FIG. 54illustrates an embodiment of a process where the operation of anautomatic cruise control system is varied in response to the body stateindex of a driver. In step 3930, response system 199 may determine thatthe automatic cruise control function is turned on. This may occur whena driver selects to turn on cruise control. In step 3931, responsesystem 199 may determine the body state index of the driver using anymethod discussed above as well as any method known in the art. In step3932, response system 199 may set the auto cruise control status basedon the body state index of the driver. For example, look-up table 3950indicates that the auto cruise control status is set to on for bodystate indexes of 1, 2 and 3. Also, the auto cruise control status is setto off for body state index of 4. In other embodiments, the auto cruisecontrol status can be set according to body state index in any othermanner.

In step 3934, response system 199 determines if the auto cruise controlstatus is on. If so, response system 199 proceeds to step 3942.Otherwise, if the auto cruise control status is off, response system 199proceeds to step 3936. In step 3936, response system 199 ramps downcontrol of automatic cruise control. For example, in some cases responsesystem 199 may slow down the vehicle gradually to a predetermined speed.In step 3938, response system 199 may turn off automatic cruise control.In some cases, in step 3940, response system 199 may inform the driverthat automatic cruise control has been deactivated using a dashboardwarning light or message displayed on a screen of some kind. In othercases, response system 199 could provide an audible warning thatautomatic cruise control has been deactivated. In still other cases ahaptic warning could be used.

If the auto cruise control status is determined to be on during step3934, response system 199 may set the auto cruise control distancesetting in step 3942. For example, look-up table 3946 provides onepossible configuration for a look-up table relating the body state indexto a distance setting. In this case, a body state index of 1 correspondsto a first distance, a body state index of 2 corresponds to a seconddistance and a body state index of 3 corresponds to a third distance.Each distance may have a substantially different value. In some cases,the value of each headway distance may increase as the body state indexincreases in order to provide more headway room for drivers who aredrowsy or otherwise inattentive. In step 3944, response system 199 mayoperate auto cruise control using the distance setting determined duringstep 3942.

A response system can include provisions for automatically reducing acruising speed in a cruise control system based on driver monitoringinformation. FIG. 55 illustrates an embodiment of a method forcontrolling a cruising speed. In some embodiments, some of the followingsteps could be accomplished by a response system 199 of a motor vehicle.In some cases, some of the following steps may be accomplished by an ECU150 of a motor vehicle. In other embodiments, some of the followingsteps could be accomplished by other components of a motor vehicle, suchas vehicle systems 172. In still other embodiments, some of thefollowing steps could be accomplished by any combination of systems orcomponents of the vehicle. It will be understood that in someembodiments one or more of the following steps may be optional. Forpurposes of reference, the following method discusses components shownin FIGS. 1 through 3, including response system 199.

In step 3902, response system 199 may receive drowsiness information. Instep 3904, response system 199 may determine if the driver is drowsy. Ifthe driver is not drowsy, response system 199 returns to step 3902,otherwise response system 199 proceeds to step 3906. In step 3906,response system 199 determines if cruise control is operating. If not,response system 199 returns back to step 3902. If cruise control isoperating, response system 199 determines the current cruising speed instep 3908. In step 3910, response system 199 retrieves a predeterminedpercentage. The predetermined percentage could have any value between 0%and 100%. In step 3912, response system 199 may reduce the cruisingspeed by the predetermined percentage. For example, if motor vehicle 100is cruising at 60 mph and the predetermined percentage is 50%, thecruising speed may be reduced to 30 mph. In other embodiments, thecruising speed could be reduced by a predetermined amount, such as by 20mph or 30 mph. In still other embodiments, the predetermined percentagecould be selected from a range of percentages according to the driverbody index. For example, if the driver is only slightly drowsy, thepredetermined percentage could be smaller than the percentage used whenthe driver is very drowsy. Using this arrangement, response system 199may automatically reduce the speed of motor vehicle 100, since slowingthe vehicle may reduce the potential risks posed by a drowsy driver.

FIG. 56 illustrates an embodiment of a process for controlling a lowspeed follow system in response to driver behavior. In step 3830,response system 199 may determine if the low speed follow system is on.“Low speed follow” refers to any system that is used for automaticallyfollowing a preceding vehicle at low speeds.

In step 3831, response system 199 may determine the body state index ofthe driver. Next, in step 3832, response system 199 may set the lowspeed follow status based on the body state index of the driver. Forexample, look-up table 3850 shows an exemplary relationship between bodystate index and the low speed follow status. In particular, the lowspeed follow status varies between an “on” state and an “off” state. Forlow body state index (body state indexes of 1 or 2) the low speed followstatus may be set to “on”. For high body state index (body state indexesof 3 or 4) the low speed follow status may be set to “off”. It will beunderstood that the relationship between body state index and low speedfollow status shown here is only exemplary and in other embodiments therelationship could vary in any other manner.

In step 3834, response system 199 determines if the low speed followstatus is on or off. If the low speed follow status is on, responsesystem 199 returns to step 3830. Otherwise, response system 199 proceedsto step 3836 when the low speed follow status is off. In step 3836,response system 199 may ramp down control of the low speed followfunction. For example, the low speed follow system may graduallyincrease the headway distance with the preceding vehicle until thesystem is shut down in step 3838. By automatically turning of low speedfollow when a driver is drowsy, response system 199 may help increasedriver attention and awareness since the driver must put more effortinto driving the vehicle.

In some cases, in step 3840, response system 199 may inform the driverthat low speed follow has been deactivated using a dashboard warninglight or message displayed on a screen of some kind. In other cases,response system 199 could provide an audible warning that low speedfollow has been deactivated.

A response system can include provisions for modifying the operation ofa lane departure warning system, which helps alert a driver if the motorvehicle is unintentionally leaving the current lane. In some cases, aresponse system could modify when the lane departure warning systemalerts a driver. For example, the lane keep departure warning systemcould warn the driver before the vehicle crosses a lane boundary line,rather than waiting until the vehicle has already crossed the laneboundary line.

FIGS. 57 and 58 illustrate schematic views of an embodiment of a methodof modifying the operation of a lane departure warning system. Referringto FIGS. 57 and 58, motor vehicle 100 travels on roadway 4000. Undercircumstances where driver 4002 is fully alert (see FIG. 57), lanedeparture warning system 240 may wait until motor vehicle 100 crosseslane boundary line 4010 before providing warning 4012. However, incircumstances where driver 4002 is drowsy (see FIG. 58), lane departurewarning system 240 may provide warning 4012 just prior to the momentwhen motor vehicle 100 crosses lane boundary line 4010. In other words,lane departure warning system 244 warns driver 4002 earlier when driver4002 is drowsy. This may help improve the likelihood that driver 4002stays inside the current lane.

FIG. 59 illustrates an embodiment of a process of operating a lanedeparture warning system in response to driver behavior. In someembodiments, some of the following steps could be accomplished by aresponse system 199 of a motor vehicle. In some cases, some of thefollowing steps may be accomplished by an ECU 150 of a motor vehicle. Inother embodiments, some of the following steps could be accomplished byother components of a motor vehicle, such as vehicle systems 172. Instill other embodiments, some of the following steps could beaccomplished by any combination of systems or components of the vehicle.It will be understood that in some embodiments one or more of thefollowing steps may be optional. For purposes of reference, thefollowing method discusses components shown in FIGS. 1 through 3,including response system 199.

In step 4202, response system 199 may retrieve drowsiness information.In step 4204, response system 199 may determine if the driver is drowsy.If the driver is not drowsy, response system 199 proceeds back to step4202. Otherwise, response system 199 proceeds to step 4206. In step4206, response system 199 may modify the operation of lane departurewarning system 240 so that the driver is warned earlier about potentiallane departures.

FIG. 60 illustrates an embodiment of a process for operating a lanedeparture warning system in response to driver behavior. In particular,FIG. 60 illustrates an embodiment of a process where the operation of alane departure warning system is modified in response to the body stateindex of a driver. In step 4270, response system 199 receives roadwayinformation. The roadway information can include road size, shape aswell as the locations of any road markings or lines. In step 4272,response system 199 may determine the vehicle position relative to theroad. In step 4274, response system 199 may calculate the time to lanecrossing. This can be determined from vehicle position, vehicle turninginformation and lane location information.

In step 4276, response system 199 may set the road crossing threshold.The road crossing threshold may be a time associated with the time tolane crossing. In step 4278, response system 199 determines if the timeto lane crossing exceeds the road crossing threshold. If not, responsesystem 199 proceeds back to step 4270. Otherwise, response system 199proceeds to step 4280 where a warning indicator is illuminatedindicating that the vehicle is crossing a lane. In other cases, audibleor haptic warnings could also be provided. If the vehicle continuesexiting the lane a steering effort correction may be applied in step4282.

FIG. 61 illustrates an embodiment of a process for setting the roadcrossing threshold. In step 4290, response system 199 determines aminimum reaction time for vehicle recovery. In some cases, the minimumreaction time is associated with the minimum amount of time for avehicle to avoid a lane crossing once a driver becomes aware of thepotential lane crossing. In step 4292, response system 199 may receivevehicle operating information. Vehicle operating information couldinclude roadway information as well as information related to thelocation of the vehicle within the roadway.

In step 4294, response system 199 determines an initial thresholdsetting from the minimum reaction time and the vehicle operatinginformation. In step 4296, response system 199 determines the body indexstate of the driver. In step 4298, response system 199 determines a lanedeparture warning coefficient according to the body state index. Anexemplary look-up table 4285 includes a range of coefficient valuesbetween 0% and 25% as a function of the body state index. Finally, instep 4299, response system 199 may set the road crossing thresholdaccording to the lane departure warning coefficient and the initialthreshold setting.

In addition to providing earlier warnings to a driver through a lanedeparture warning system, response system 199 can also modify theoperation of a lane keep assist system, which may also provide warningsas well as driving assistance in order to maintain a vehicle in apredetermined lane.

FIG. 62 illustrates an embodiment of a process of operating a lane keepassist system in response to driver behavior. In particular, FIG. 62illustrates a method where the operation of a lane keep assist system ismodified in response to the body state index of a driver. In step 4230,response system 199 may receive operating information. For example, insome cases response system 199 may receive roadway information relatedto the size and/or shape of a roadway, as well as the location ofvarious lines on the roadway. In step 4232, response system 199determines the location of the road center and the width of the road.This can be determined using sensed information, such as opticalinformation of the roadway, stored information including map basedinformation, or a combination of sensed and stored information. In step4234, response system 199 may determine the vehicle position relative tothe road.

In step 4236, response system 199 may determine the deviation of thevehicle path from the road center. In step 4238, response system 199 maylearn the driver's centering habits. For example, alert driversgenerally adjust the steering wheel constantly in attempt to maintainthe car in the center of a lane. In some cases, the centering habits ofa driver can be detected by response system 199 and learned. Any machinelearning method or pattern recognition algorithm could be used todetermine the driver's centering habits.

In step 4240, response system 199 may determine if the vehicle isdeviating from the center of the road. If not, response system 199proceeds back to step 4230. If the vehicle is deviating, response system199 proceeds to step 4242. In step 4242, response system 199 maydetermine the body state index of the driver. Next, in step 4244,response system 199 may set the lane keep assist status using the bodystate index. For example, look-up table 4260 is an example of arelationship between body state index and lane keep assist status. Inparticular, the lane keep assist status is set to a standard state forlow body state index (indexes 1 or 2) and is set to a low state for ahigher body state index (indexes 3 or 4). In other embodiments, anyother relationship between body state index and lane keep assist statuscan be used.

In step 4246, response system 199 may check the lane keep assist status.If the lane keep assist status is standard, response system 199 proceedsto step 4248 where standard steering effort corrections are applied tohelp maintain the vehicle in the lane. If, however, response system 199determines that the lane keep assist status is low in step 4246,response system 199 may proceed to step 4250. In step 4250, responsesystem 199 determines if the road is curved. If not, response system 199proceeds to step 4256 to illuminate a lane keep assist warning so thedriver knows the vehicle is deviating from the lane. If, in step 4250,response system 199 determines the road is curved, response system 199proceeds to step 4252. In step 4252, response system 199 determines ifthe driver's hands are on the steering wheel. If so, response system 199proceeds to step 4254 where the process ends. Otherwise, response system199 proceeds to step 4256.

This arrangement allows response system 199 to modify the operation ofthe lane keep assist system in response to driver behavior. Inparticular, the lane keep assist system may only help steer the vehicleautomatically when the driver state is alert (low body state index).Otherwise, if the driver is drowsy or very drowsy (higher body stateindex), response system 199 may control the lane keep assist system toonly provide warnings of lane deviation without providing steeringassistance. This may help increase the alertness of the driver when heor she is drowsy.

A response system can include provisions for modifying the control of ablind spot indicator system when a driver is drowsy. For example, insome cases, a response system could increase the detection area. Inother cases, the response system could control the monitoring system todeliver warnings earlier (i.e., when an approaching vehicle is furtheraway).

FIGS. 63 and 64 illustrate schematic views of an embodiment of theoperation of a blind spot indicator system. In this embodiment, motorvehicle 100 is traveling on roadway 4320. Blind spot indicator system242 (see FIG. 2) may be used to monitor any objects traveling withinblind spot monitoring zone 4322. For example, in the current embodiment,blind spot indicator system 242 may determine that no object is insideof blind spot monitoring zone 4322. In particular, target vehicle 4324is just outside of blind spot monitoring zone 4322. In this case, noalert is sent to the driver.

In FIG. 63, driver 4330 is shown as fully alert. In this alert state,the blind spot monitoring zone is set according to predeterminedsettings and/or vehicle operating information. However, as seen in FIG.64, as driver 4330 becomes drowsy, response system 199 may modify theoperation of blind spot indicator system 242. For example, in oneembodiment, response system 199 may increase the size of blind spotmonitoring zone 4322. As seen in FIG. 64, under these modifiedconditions target vehicle 4324 is now traveling inside of blind spotmonitoring zone 4322. Therefore, in this situation driver 4330 isalerted to the presence of target vehicle 4324.

FIG. 65 illustrates an embodiment of a process of operating a blind spotindicator system in response to driver behavior. In some embodiments,some of the following steps could be accomplished by a response system199 of a motor vehicle. In some cases, some of the following steps maybe accomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 4302, response system 199 may receive drowsiness information. Instep 4304, response system 199 determines if the driver is drowsy. Ifthe driver is not drowsy, response system 199 returns back to step 4302.If the driver is drowsy, response system 199 proceeds to step 4306. Instep 4306, response system 4306 may increase the blind spot detectionarea. For example, if the initial blind spot detection area isassociated with the region of the vehicle between the passenger sidemirror about 3-5 meters behind the rear bumper, the modified blind spotdetection area may be associated with the region of the vehicle betweenthe passenger side mirror and about 4-7 meters behind the rear bumper.Following this, in step 4308, response system 199 may modify theoperation of blind spot indicator system 242 so that the system warns adriver when a vehicle is further away. In other words, if the systeminitially warns a driver if the approaching vehicle is within 5 metersof motor vehicle 100, or the blind spot, the system may be modified towarn the driver when the approaching vehicle is within 10 meters ofmotor vehicle 100, or the blind spot of motor vehicle 100. Of course, itwill be understood that in some cases, step 4306 or step 4308 may beoptional steps. In addition, other sizes and locations of the blind spotzone are possible.

FIG. 66 illustrates an embodiment of a process of operating a blind spotindicator system in response to driver behavior as a function of thebody state index of the driver. In step 4418, response system 199receives object information. This information can include informationfrom one or more sensors capable of detecting the location of variousobjects (including other vehicles) within the vicinity of the vehicle.In some cases, for example, response system 199 receives informationfrom a remote sensing device (such as a camera, lidar or radar) fordetecting the presence of one or more objects.

In step 4420, response system 199 may determine the location and/orbearing of a tracked object. In step 4422, response system 199 sets azone threshold. The zone threshold may be a location threshold fordetermining when an object has entered into a blind spot monitoringzone. In some cases, the zone threshold may be determined using the bodystate index of the driver as well as information about the trackedobject.

In step 4424, response system 199 determines if the tracked objectcrosses the zone threshold. If not, response system 199 proceeds to step4418. Otherwise, response system 199 proceeds to step 4426. In step4426, response system 199 determines if the relative speed of the objectis in a predetermined range. If the relative speed of the object is inthe predetermined range, it is likely to stay in the blind spotmonitoring zone for a long time and may pose a very high threat.Response system 199 may ignore objects with a relative speed outside thepredetermined range, since the object is not likely to stay in the blindspot monitoring zone for very long. If the relative speed is not in thepredetermined range, response system 199 proceeds back to step 4418.Otherwise, response system 199 proceeds to step 4428.

In step 4428, response system 199 determines a warning type using thebody state index. In step 4430, response system 199 sets the warningintensity and frequency using the body state index. Lookup table 4440 isan example of a relationship between body state index and a coefficientfor warning intensity. Finally, in step 4432, response system 199activates the blind spot indicator warning to alert the driver of thepresence of the object in the blind spot.

FIG. 67 illustrates an embodiment of a process for determining a zonethreshold. In step 4450, response system 199 retrieves tracked objectinformation. In step 4452, response system 199 may determine an initialthreshold setting. In step 4454, response system 199 may determine thebody state index of the driver. In step 4456, response system 199 maydetermine a blind spot zone coefficient. For example, look-up table 4460includes a predetermined relationship between body state index and theblind spot zone coefficient. The blind spot zone coefficient may rangebetween 0% and 25% in some cases and may generally increase with thebody state index. Finally, in step 4458, response system 199 maydetermine the zone threshold.

Generally, the zone threshold can be determined using the initialthreshold setting (determined in step 4452) and the blind spot zonecoefficient. For example, if the blind spot zone coefficient has a valueof 25%, the zone threshold may be up to 25% larger than the initialthreshold setting. In other cases, the zone threshold may be up to 25%smaller than the initial threshold setting. In other words, the zonethreshold may be increased or decreased from the initial thresholdsetting in proportion to the value of the blind spot zone coefficient.Moreover, as the value of the zone threshold changes, the size of theblind spot zone or blind spot detection area may change. For example, insome cases, as the value of the zone threshold increases, the length ofthe blind spot detection area is increased, resulting in a largerdetection area and higher system sensitivity. Likewise, in some cases,as the value of the zone threshold decreases, the length of the blindspot detection area is decreased, resulting in a smaller detection areaand lower system sensitivity.

FIG. 68 illustrates an example of an embodiment of various warningsettings according to the body state index in the form of lookup table4470. For example, when the driver's body state index is 1, the warningtype may be set to indicator only. In other words, when the driver isnot drowsy, the warning type may be set to light-up one or more warningindicators only. When the body state index is 2, both indicators andsounds may be used. When the driver's body state index is 3, indicatorsand haptic feedback may be used. For example, a dashboard light mayflash and the driver's seat or the steering wheel may vibrate. When thedriver's body state index is 4, indicators, sounds and haptic feedbackmay all be used. In other words, as the driver becomes more drowsy(increased body state index), a greater variety of warning types may beused simultaneously. It will be understood that the present embodimentonly illustrates exemplary warning types for different body stateindexes and in other embodiments any other configuration of warningtypes for body state indexes can be used.

FIGS. 69 through 72 illustrate exemplary embodiments of the operation ofa collision mitigation braking system (CMBS) in response to driverbehavior. In some cases, a collision mitigation braking system could beused in combination with a forward collision warning system. Inparticular, in some cases, a collision mitigation braking system couldgenerate forward collision warnings in combination with, or instead of,a forward collision warning system. Moreover, the collision mitigationbraking system could be configured to further actuate various systems,including braking systems and electronic seatbelt pretensioning systems,in order to help avoid a collision. In other cases, however, a collisionmitigation braking system and a forward collision warning system couldbe operated as independent systems. In the exemplary situationsdiscussed below, a collision mitigation braking system is capable ofwarning a driver of a potential forward collision. However, in othercases, a forward collision warning could be provided by a separateforward collision warning system.

As seen in FIG. 69, motor vehicle 100 is driving behind target vehicle4520. In this situation, motor vehicle 100 is traveling at approximately60 mph, while target vehicle 4520 is slowing to approximately 30 mph. Atthis point, motor vehicle 100 and target vehicle 4520 are separated bydistance D1. Because the driver is alert, however, CMBS 236 determinesthat distance D1 is not small enough to require a forward collisionwarning. In contrast, when the driver is drowsy, as seen in FIG. 70,response system 199 may modify the operation of the CMBS 236 so that awarning 4530 is generated during a first warning stage of CMBS 236. Inother words, CMBS 236 becomes more sensitive when the driver is drowsy.Moreover, as discussed below, the level of sensitivity may vary inproportion to the degree of drowsiness (indicated by the body stateindex).

Referring now to FIG. 71, motor vehicle 100 continues to approach targetvehicle 4520. At this point, motor vehicle 100 and target vehicle 4520are separated by distance D2. This distance is below the threshold foractivating a forward collision warning 4802. In some cases, the warningcould be provided as a visual alert and/or an audible alert. However,because the driver is alert, distance D2 is not determined to be smallenough to activate additional collision mitigation provisions, such asautomatic braking and/or automatic seatbelt pretensioning. In contrast,when the driver is drowsy, as seen in FIG. 72, response system 199 maymodify the operation of CMBS 236 so that in addition to providingforward collision warning 4802, CMBS 236 may also automaticallypretension seatbelt 4804. Also, in some cases, CMBS 236 may apply lightbraking 4806 to slow motor vehicle 100. In other cases, however, nobraking may be applied at this point.

For purposes of illustration, the distance between vehicles is used asthe threshold for determining if response system 199 should issue awarning and/or apply other types of intervention. However, it will beunderstood that in some cases, the time to collision between vehiclesmay be used as the threshold for determining what actions responsesystem 199 may perform. In some cases, for example, using informationabout the velocities of the host and target vehicles as well as therelative distance between the vehicles can be used to estimate a time tocollision. Response system 199 may determine if warnings and/or otheroperations should be performed according to the estimated time tocollision.

FIG. 73 illustrates an embodiment of a process for operating a collisionmitigation braking system in response to driver behavior. In step 4550,response system 199 may receive target vehicle information and hostvehicle information. For example, in some cases response system 199 mayreceive the speed, location and/or bearing of the target vehicle as wellas the host vehicle. In step 4552, response system 199 may determine thelocation of an object in the sensing area, such as a target vehicle. Instep 4554, response system 199 may determine the time to collision withthe target vehicle.

In step 4556, response system 199 may set a first time to collisionthreshold and a second time to collision threshold. In some cases, thefirst time to collision threshold may be greater than the second time tocollision threshold. However, in other cases, the first time tocollision threshold may be less than or equal to the second time tocollision threshold. Details for determining the first time to collisionthreshold and the second time to collision threshold are discussed belowand shown in FIG. 74.

In step 4558, response system 199 may determine if the time to collisionis less than the first time to collision threshold. If not, responsesystem 199 returns to step 4550. In some cases, the first time tocollision threshold may a value above which there is no immediate threatof a collision. If the time to collision is less than the first time tocollision threshold, response system 199 proceeds to step 4560.

At step 4560, response system 199 may determine if the time to collisionis less than the second time to collision threshold. If not, responsesystem 199 enters a first warning stage at step 4562. The responsesystem 199 may then proceed through further steps discussed below andshown in FIG. 75. If the time to collision is greater than the secondtime to collision threshold, response system 199 may enter a secondwarning stage at step 4564. Response system 199 may then proceed throughfurther steps discussed below and shown in FIG. 76.

FIG. 74 illustrates an embodiment of a process for setting a first timeto collision threshold and a second time to collision threshold. In step4580, response system 199 may determine a minimum reaction time foravoiding a collision. In step 4582, response system 199 may receivetarget and host vehicle information such as location, relative speeds,absolute speeds as well as any other information. In step 4584, responsesystem 199 may determine a first initial threshold setting and a secondinitial threshold setting. In some cases, the first initial thresholdsetting corresponds to the threshold setting for warning a driver. Insome cases, the second initial threshold setting corresponds to thethreshold setting for warning a driver and also operating braking and/orseatbelt pretensioning. In some cases, these initial threshold settingsmay function as default setting that may be used with a driver is fullyalert. Next, in step 4586, response system 199 may determine the bodystate index of the driver.

In step 4588, response system 199 may determine a time to collisioncoefficient. In some cases, the time to collision coefficient can bedetermined using look-up table 4592, which relates the time to collisioncoefficient to the body state index of the driver. In some cases, thetime to collision coefficient increases from 0% to 25% as the body stateindex increases. In step 4590, response system 199 may set the firsttime to collision threshold and the second time to collision threshold.Although a single time to collision coefficient is used in thisembodiment, the first time to collision threshold and the second time tocollision threshold may differ according to the first initial thresholdsetting and the second initial threshold setting, respectively. Usingthis configuration, in some cases, the first time to collision thresholdand the second time to collision threshold may be decreased as the bodystate index of a driver increases. This allows response system 199 toprovide earlier warnings of potential hazards when a driver is drowsy.Moreover, the timing of the warnings varies in proportion to the bodystate index.

FIG. 75 illustrates an embodiment of a process for operating a motorvehicle in a first warning stage of CMBS 236. In step 4702, responsesystem 199 may select visual and/or audible warnings for alerting adriver of a potential forward collision. In some cases, a warning lightmay be used. In other cases, an audible noise, such as a beep, could beused. In still other cases, both a warning light and a beep could beused.

In step 4704, response system 199 may set the warning frequency andintensity. This may be determined using the body state index in somecases. In particular, as the driver state increases due to the increaseddrowsiness of the driver, the warning state frequency and intensity canbe increased. For example, in some cases look-up table 4570 can be usedto determine the warning frequency and intensity. In particular, in somecases as the warning intensity coefficient increases (as a function ofbody state index), the intensity of any warning can be increased by upto 25%. In step 4706, response system 199 may apply a warning forforward collision awareness. In some cases, the intensity of the warningcan be increased for situations where the warning intensity coefficientis large. For example, for a low warning intensity coefficient (0%) thewarning intensity may be set to a predetermined level. For higherwarning intensity coefficients (greater than 0%) the warning intensitymay be increased beyond the predetermined level. In some cases, theluminosity of visual indicators can be increased. In other cases, thevolume of audible warnings can be increased. In still other cases, thepattern of illuminating a visual indicator or making an audible warningcould be varied.

FIG. 76 illustrates an embodiment of process of operating a motorvehicle in a second stage of CMBS 236. In some cases, during step 4718,CMBS 236 may use visual and/or audible warnings to alert a driver of apotential collision. In some cases, the level and/or intensity of thewarnings could be set according to the driver state index, as discussedabove and shown in step 4704 of FIG. 75. Next, in step 4720, responsesystem 199 may use a haptic warning. In situations where visual and/oraudible warnings are also used, the haptic warning can be providedsimultaneously with the visual and/or audible warnings. In step 4722,response system 199 may set the warning frequency and intensity of thehaptic warning. This may be achieved using look-up table 4570, forexample. Next, in step 4724, response system 199 may automaticallypretension a seatbelt in order to warn the driver. The frequency andintensity of the tensioning may vary as determined in step 4722. In step4726, response system 199 may apply light braking automatically in orderto slow the vehicle. In some cases, step 4726 may be optional step.

FIG. 77 illustrates an embodiment of a process of operating a navigationsystem in response to driver behavior. In some embodiments, some of thefollowing steps could be accomplished by a response system 199 of amotor vehicle. In some cases, some of the following steps may beaccomplished by an ECU 150 of a motor vehicle. In other embodiments,some of the following steps could be accomplished by other components ofa motor vehicle, such as vehicle systems 172. In still otherembodiments, some of the following steps could be accomplished by anycombination of systems or components of the vehicle. It will beunderstood that in some embodiments one or more of the following stepsmay be optional. For purposes of reference, the following methoddiscusses components shown in FIGS. 1 through 3, including responsesystem 199.

In step 4602, response system 199 may receive drowsiness information. Instep 4604, response system 199 may determine if the driver is drowsy. Ifthe driver is not drowsy, response system 199 proceeds back to step4602. Otherwise, response system 199 proceeds to step 4606. In step4606, response system 199 may turn off navigation system 4606. This mayhelp reduce driver distraction.

It will be understood that in some embodiments, multiple vehicle systemscould be modified according to driver behavior substantiallysimultaneously. For example, in some cases when a driver is drowsy, aresponse system could modify the operation of a collision warning systemand a lane keep assist system to alert a driver earlier of any potentialcollision threats or unintentional lane departures. Likewise, in somecases when a driver is drowsy, a response system could automaticallymodify the operation of an antilock brake system and a brake assistsystem to increase braking response. The number of vehicle systems thatcan be simultaneously activated in response to driver behavior is notlimited.

It will be understood that the current embodiment illustrates anddiscusses provisions for sensing driver behavior and modifying theoperation of one or more vehicle systems accordingly. However, thesemethods are not limited to use with a driver. In other embodiments,these same methods could be applied to any occupant of a vehicle. Inother words, a response system may be configured to detect if variousother occupants of a motor vehicle are drowsy. Moreover, in some cases,one or more vehicle systems could be modified accordingly.

While various embodiments have been described, the description isintended to be exemplary, rather than limiting and it will be apparentto those of ordinary skill in the art that many more embodiments andimplementations are possible that are within the scope of theembodiments. Accordingly, the embodiments are not to be restrictedexcept in light of the attached claims and their equivalents. Also,various modifications and changes may be made within the scope of theattached claims.

The invention claimed is:
 1. A method of controlling a vehicle system ina vehicle, comprising: receiving monitoring information about a state ofa driver from a monitoring system of the vehicle; receiving vehicleoperating information about the vehicle system and the state of thedriver from the vehicle system; calculating a driver state indexcomprising the monitoring information about the state of the driver andthe vehicle operating information about the vehicle system and the stateof the driver; determining a control coefficient using the driver stateindex; changing a control parameter of the vehicle system using thedriver state index and the control coefficient, wherein the controlparameter is a system status of the vehicle system; and modifyingcontrol of the vehicle system using the control parameter.
 2. The methodof claim 1, wherein the vehicle system provides driving assistance tothe driver and changing the control parameter of the vehicle systembased on the driver state index includes changing a level of drivingassistance.
 3. The method of claim 1, including determining if thedriver is distracted based on driver state index and changing thecontrol parameter of the vehicle system based on the driver state indexwhen the driver is distracted.
 4. The method of claim 3, whereinchanging the control parameter of the vehicle system based on the driverstate index includes changing the system status from ON to OFF when thedriver is distracted.
 5. The method of claim 1, including determining aninitial system status of the vehicle system based on the vehicleoperating information, and wherein changing the control parameter of thevehicle system based on the driver state index includes changing thesystem status from the initial system status based on the driver stateindex.
 6. The method of claim 5, wherein the initial system status ofthe vehicle system is ON and changing the system status from the initialsystem status based on the driver state index includes setting thesystem status to OFF.
 7. The method of claim 1, wherein the vehiclesystem is an electronic power steering system, and changing the controlparameter of the vehicle system based on the driver state index includeschanging the system status of the electronic power steering system to alow system status, and modifying the vehicle system based on the controlparameter includes modifying the electronic power steering systemaccording to the low system status thereby decreasing an amount of powerassistance.
 8. The method of claim 1, wherein the vehicle system is alow speed follow system, and changing the control parameter of thevehicle system based on the driver state index includes changing thesystem status of the low speed follow system to OFF, and modifying thevehicle system based on the control parameter includes deactivating thelow speed follow system.
 9. The method of claim 1, wherein the vehiclesystem is auto cruise control system, and changing the control parameterof the vehicle system based on the driver state index includes changingthe system status of the auto cruise control system to OFF, andmodifying the vehicle system based on the control parameter includesswitching the auto cruise control system to OFF.
 10. The method of claim1, wherein the monitoring system includes a portable sensor that is wornby the driver that monitors information about the state of the driver,and calculating the driver state index of the driver includescalculating the driver state index of the driver using information aboutthe state for driver from the portable sensor.
 11. A response system forcontrolling a vehicle system in a vehicle, comprising: a monitoringsystem including one or more sensors that detect monitoring information,wherein the monitoring information is information about a state of adriver; and an electronic control unit that receives the monitoringinformation from the monitoring system and vehicle operating informationabout the vehicle system and the state of the driver from the vehicle,determines a driver state index of the driver comprising the monitoringinformation about the state of the driver and the vehicle operatinginformation about the vehicle system and the state of the driver,determines a control coefficient using the driver state index, andmodifies a control parameter of the vehicle system based on the driverstate index and the control coefficient, wherein the control parameteris a value that defines an operational state of the vehicle system, andwherein the electronic control unit controls the vehicle system usingthe control parameter.
 12. The response system of claim 11, wherein theelectronic control unit further determines if the driver is distractedbased on driver state index and controls the vehicle system using thecontrol parameter when the driver is distracted.
 13. The response systemof claim 11, wherein the vehicle system provides driving assistance tothe driver, and the electronic control unit further determines if thedriver is distracted based on driver state index and controls thevehicle system using the control parameter to reduce driving assistancewhen the driver is distracted.
 14. The response system of claim 11,wherein the value that defines the operational state of the vehiclesystem is an amount of driving assistance provided by the vehiclesystem, and the electronic control unit modifies the control parameterof the vehicle system based on the driver state index by decreasing theamount of driving assistance provided by the vehicle system according tothe driver state index.
 15. The response system of claim 11, wherein theelectronic control unit further determines an initial control parameterof the vehicle system, wherein the initial control parameter is an ONoperational state or an OFF operational state of the vehicle system, andthe electronic control unit modifies the control parameter of thevehicle system based on the driver state index by setting the controlparameter to an operational state opposite of the initial controlparameter.
 16. The response system of claim 11, including a portablesensor that is worn by the driver that detects monitoring information,wherein the monitoring information detected by the portable sensor isinformation about the state of the driver, and the electronic controlunit further receives the monitoring information from the portablesensor and further determines the driver state index of the driver usingthe monitoring information from the portable sensor.
 17. The responsesystem of claim 11, wherein the vehicle system is an electronic powersteering system and the control parameter is an amount of steeringassistance applied by the electronic power steering system, and whereinthe electronic control unit modifies the control parameter of theelectronic power steering system by decreasing the amount of steeringassistance applied by the electronic power steering system when thedriver is distracted.
 18. The response system of claim 11, wherein thevehicle system is a low speed follow system, and wherein the electroniccontrol unit modifies the control parameter of the low speed followsystem to OFF when the driver is distracted.